Semiconductor device

ABSTRACT

A semiconductor device includes a first conductive plate, a second conductive plate, first switching elements, second switching elements, a first supply terminal and a second supply terminal. The first and second conductive plates are spaced apart from each other in a first direction. The first switching elements are bonded to the first conductive plate, and are electrically connected to the second conductive plate. The second switching elements are bonded to the second conductive plate. The first supply terminal is bonded to the first conductive plate. The second supply terminal has a region that overlaps with the first supply terminal as viewed in a plan view. The second supply terminal is spaced apart from the first conductive plate and the first supply terminal in a thickness direction perpendicular to the first direction. The second supply terminal is electrically connected to the second switching elements.

TECHNICAL FIELD

The present invention relates to a semiconductor device provided with aplurality of switching elements.

BACKGROUND ART

Conventionally, a variety of semiconductor devices (power modules)provided with a plurality of switching elements (power MOSFETs or IGBTs)have been proposed. Such semiconductor devices can be used to form partof an apparatus for performing power conversion such as a DC-DCconverter. For example, Patent Document 1 below discloses an example ofa conventional semiconductor device provided with a plurality ofswitching elements. In this conventional semiconductor device, aconductive layer made of a metal foil is formed on an insulatingsubstrate, and the plurality of switching elements are joined to thisconductive layer.

Heat is generated by the switching elements while the switching elementsoperate, and the temperature of the conductive layer increases. Since, athin metal foil is used as the conductive layer in the above-describedconventional semiconductor device, the conductive layer has relativelyhigh resistance to heat conduction. Accordingly, the conductive layertends to stay to be in a high temperature state in the vicinity ofswitching elements in operation.

PRIOR ART DOCUMENTS Patent Document

Patent Document 1: JP-2009-158787A

SUMMARY OF INVENTION Problem to be Solved by Invention

In view of the above-described circumstances, the present invention aimsto provide a semiconductor device that has an improved heat dissipation,compared to conventional ones.

Means for Solving Problem

A semiconductor device that is provided according to a first aspect ofthe present invention includes: an insulating layer that has a mainsurface oriented in a thickness direction; a first conductive plate anda second conductive plate that are bonded to the main surface, and arespaced apart from each other in a first direction perpendicular to thethickness direction; a plurality of first switching elements that areelectrically bonded to the first conductive plate, and are electricallyconnected to the second conductive plate; a plurality of secondswitching elements that are electrically bonded to the second conductiveplate; a first supply terminal that is electrically bonded to the firstconductive plate; and a second supply terminal that is spaced apart fromboth the first conductive plate and the first supply terminal in thethickness direction, and is electrically connected to the plurality ofsecond switching elements, where the first conductive plate and thesecond conductive plate have a thickness that is larger than a thicknessof the insulating layer.

A semiconductor device that is provided according to a second aspect ofthe present invention includes: a first conductive plate that has afirst main surface perpendicular to a thickness direction of the firstconductive plate; a second conductive plate that has a second mainsurface perpendicular to the thickness direction, and is spaced apartfrom the first conductive plate in a first direction perpendicular tothe thickness direction; a plurality of first switching elements thatare electrically bonded to the first conductive plate, and areelectrically connected to the second conductive plate; and a pluralityof second switching elements that are electrically bonded to the secondconductive plate; a first supply terminal that is electrically bonded tothe first conductive plate; and a second supply terminal that has aregion that overlaps with the first supply terminal as viewed in thethickness direction, and is spaced apart from the first conductive plateand the first supply terminal in the thickness direction, where thesecond supply terminal is electrically connected to the plurality ofsecond switching elements.

The other features and advantages of the present invention will becomeapparent from the detailed description given below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a semiconductor deviceaccording to a first embodiment of a first aspect.

FIG. 2 is a plan view of the semiconductor device.

FIG. 3 is a bottom view of the semiconductor device.

FIG. 4 is a front view of the semiconductor device.

FIG. 5 is a side view of the semiconductor device.

FIG. 6 is a plan view of the semiconductor device, with a sealing resinbeing transparent.

FIG. 7 is a plan view that corresponds to FIG. 6, with a second supplyterminal omitted and a terminal insulating member being transparent.

FIG. 8 is a cross-sectional view taken along a line VIII-VIII in FIG. 6.

FIG. 9 is an enlarged view of a portion shown in FIG. 8.

FIG. 10A is a cross-sectional view taken along a line X-X in FIG. 6,illustrating the vicinity of a first conductive plate.

FIG. 10B is a cross-sectional view taken along the line X-X in FIG. 6,illustrating the vicinity of a second conductive plate.

FIG. 11 is an enlarged view of a portion shown in FIG. 10B.

FIG. 12 is a plan view illustrating a first switching element.

FIG. 13 is a plan view illustrating a second switching element.

FIG. 14 is a circuit diagram of the semiconductor device.

FIG. 15 is a schematic view illustrating an example of usage of thesemiconductor device.

FIG. 16 is a plan view illustrating a semiconductor device according toa second embodiment of the first aspect, with a sealing resin beingtransparent.

FIG. 17 is a cross-sectional view taken along a line XVII-XVII in FIG.16.

FIG. 18 is an enlarged view of a portion shown in FIG. 17.

FIG. 19 is a cross-sectional view taken along a line XIX-XIX in FIG. 16.

FIG. 20 is an enlarged view of a portion shown in FIG. 19.

FIG. 21 is a plan view illustrating a semiconductor device according toa third embodiment of the first aspect, with a sealing resin beingtransparent.

FIG. 22 is a cross-sectional view taken along a line XXII-XXII in FIG.21.

FIG. 23 is an enlarged view of a portion shown in FIG. 22.

FIG. 24 is a plan view illustrating a semiconductor device according toa fourth embodiment of the first aspect, with a sealing resin beingtransparent.

FIG. 25 is a bottom view of the semiconductor device shown in FIG. 24.

FIG. 26 is a front view of the semiconductor device shown in FIG. 24.

FIG. 27 is a right side view of the semiconductor device shown in FIG.24.

FIG. 28A is a cross-sectional view taken along a line XXVIII-XXVIII inFIG. 24, illustrating the vicinity of a first conductive plate.

FIG. 28B is a cross-sectional view taken along the line XXVIII-XXVIII inFIG. 24, illustrating the vicinity of a second conductive plate.

FIG. 29 is an enlarged view of a portion shown in FIG. 28B.

FIG. 30 is a plan view illustrating a semiconductor device according toa fifth embodiment of the first aspect, with a sealing resin beingtransparent.

FIG. 31A is a cross-sectional view taken along a line XXXI-XXXI in FIG.30, illustrating the vicinity of a first conductive plate.

FIG. 31B is a cross-sectional view taken along the line XXXI-XXXI inFIG. 30, illustrating the vicinity of a second conductive plate.

FIG. 32 is an enlarged view of a portion shown in FIG. 31B.

FIG. 33 is a bottom view illustrating a semiconductor device accordingto a first embodiment of a second aspect.

FIG. 34 is a plan view of the semiconductor device shown in FIG. 33,with a sealing resin being transparent.

FIG. 35 is a plan view that corresponds to FIG. 34, with a second supplyterminal omitted and a terminal insulating member being transparent.

FIG. 36 is a cross-sectional view taken along a line XXXVI-XXXVI in FIG.34.

FIG. 37 is a partially enlarged view of FIG. 36.

FIG. 38 is a cross-sectional view taken along a line XXXVIII,XXXIX-XXXVIII, XXXIX in FIG. 34, illustrating the vicinity of a firstconductive plate.

FIG. 39 is a cross-sectional view taken along the line XXXVIII,XXXIX-XXXVIII, XXXIX in FIG. 34, illustrating the vicinity of a secondconductive plate.

FIG. 40 is an enlarged view of a portion shown in FIG. 39.

FIG. 41 is a plan view illustrating a first switching element shown inFIG. 34.

FIG. 42 is a plan view illustrating a second switching element shown inFIG. 34.

FIG. 43 is a plan view illustrating a semiconductor device according toa second embodiment of the second aspect, with a sealing resin beingtransparent.

FIG. 44 is a cross-sectional view taken along a line XLIV-XLIV in FIG.43.

FIG. 45 is an enlarged view of a portion shown in FIG. 44.

FIG. 46 is a cross-sectional view taken along a line XLVI-XLVI in FIG.43.

FIG. 47 is an enlarged view of a portion shown in FIG. 46.

FIG. 48 is a plan view illustrating a semiconductor device according toa third embodiment of the second aspect, with a sealing resin beingtransparent.

FIG. 49 is a cross-sectional view taken along a line XLIX-XLIX in FIG.48.

FIG. 50 is an enlarged view of a portion shown in FIG. 49.

MODE FOR CARRYING OUT INVENTION

Embodiments of the present invention will be described with reference tothe accompanying drawings.

A semiconductor device A10 according to a first embodiment of a firstaspect will be described with reference to FIGS. 1 to 13. Thesemiconductor device A10 is provided with an insulating layer(insulating substrate) 10, a first conductive plate 11, a secondconductive plate 12, a plurality of first switching elements 21, aplurality of second switching elements 22, a first supply terminal 31,and a second supply terminal 32. In addition thereto, the semiconductordevice A10 is provided with an insulating material 15 (see e.g. FIG. 9),a terminal insulating member 39 (see e.g. FIG. 1), a plurality of firstconductive wires 411, a plurality of second conductive wires 421, and asealing resin 50. In FIG. 6, the sealing resin 50 is transparent, forconvenience of understanding. Furthermore, in FIG. 7, the second supplyterminal 32 is omitted and the terminal insulating member 39 istransparent. The sealing resin 50 that is transparent in FIGS. 6 and 7,and the terminal insulating member 39 that is transparent in FIG. 7 areindicated by virtual lines (dashed-two dotted lines).

The semiconductor device A10 is a power module for performing powerconversion. As shown in FIG. 1 for example, the semiconductor device A10has a relatively small thickness (size in a thickness direction z). Adirection that is perpendicular to the thickness direction z and inwhich the first supply terminal 31 (or the second supply terminal 32)and an output terminal 33 extend is referred to as a “first directionx”. Furthermore, a direction that is perpendicular to both the thicknessdirection z and the first direction x is referred to as a “seconddirection y”. Note that, in the following description, the expression“as viewed in the thickness direction” has the same meaning as theexpression “as viewed in a plan view”.

As shown in FIGS. 6 to 11, an insulating layer 10 is a plate-shapedelectrically insulating member on which the first conductive plate 11and the second conductive plate 12 are mounted. The insulating layer 10is made of a material that has relatively high thermal conductivity.Examples of the constituent material of the insulating layer 10 includea ceramic such as Al₂O₃ (alumina) or AlN (aluminum nitride), and a heatdissipation sheet whose main component is a synthetic resin. Theinsulating layer 10 has a thickness t0 (size in the thickness directionz) of 0.25 to 0.5 mm if the constituent material thereof is a ceramic,and of 100 to 200 μm if the constituent material thereof is a heatdissipation sheet. The first conductive plate 11 and the secondconductive plate 12 are electrically insulated from the outside of thesemiconductor device A10 by the insulating layer 10. The insulatinglayer 10 has a main surface 101 and a back surface 102 that are spacedapart from each other in the thickness direction z. In FIG. 9 forexample, the main surface 101 is oriented upward, and the back surface102 is oriented downward.

As shown in FIGS. 6 to 10A, the first conductive plate 11 is anelectrically conductive member that is made of metal and isplate-shaped, and on which the plurality of first switching elements 21are mounted. The first conductive plate 11 is bonded to the main surface101 of the insulating layer 10. The constituent material of the firstconductive plate 11 is Cu (copper). The first conductive plate 11 has athickness t1 that is 1.5 to 10 mm and is larger than the thickness t0 ofthe insulating layer 10. In other words, the thickness t1 of the firstconductive plate 11 is three to one hundred times as large as thethickness t0 of the insulating layer 10. The thickness t1 of the firstconductive plate 11 is larger than the thickness (0.25 to 0.8 mm) of aconductive layer that is made of, for example, a metal foil.

As shown in FIGS. 6 to 10A (excluding FIG. 9), a first substrate 13,which has electrical insulating properties, is bonded to the firstconductive plate 11. The first substrate 13 is located between theplurality of first switching elements 21 and the first supply terminal31 in the first direction x, and extends in the second direction y. Thefirst substrate 13 is a ceramic substrate whose constituent material is,for example, Al₂O₃ or the like, or a printed-wiring board. The firstsubstrate 13 is bonded, using an adhesive (not-shown), to the side ofthe first conductive plate 11 that is opposite to the insulating layer10 in the thickness direction z. A first gate layer 131 and a firstdetection layer 132 are arranged on the first substrate 13. The firstgate layer 131 and the first detection layer 132 are electricallyconductive, and extend in the second direction y. The first gate layer131 and the first detection layer 132 are made of a Cu foil, forexample. In the first direction x, the first gate layer 131 is locatedat a position closer to the first supply terminal 31 than the firstdetection layer 132 is. In the shown example, the first gate layer 131is adjacent to the first supply terminal 31 in the first direction x.Similarly, the first detection layer 132 is adjacent to the plurality offirst switching elements 21 in the first direction x.

As shown in FIGS. 6, 7, 10B, and 11, the second conductive plate 12 isan electrically conductive member that is made of metal and isplate-shaped, and on which the plurality of second switching elements 22are mounted. The second conductive plate 12 is bonded to the mainsurface 101 of the insulating layer 10. The constituent material of thesecond conductive plate 12 is the same as the constituent material ofthe first conductive plate 11. Furthermore, the second conductive plate12 has a thickness t2 that is equal to the thickness t1 of the firstconductive plate 11. Accordingly, the thickness t2 of the secondconductive plate 12 is larger than the thickness t0 of the insulatinglayer 10, and is larger than the thickness of a conductive layer made ofa metal foil. The second conductive plate 12 is spaced apart from thefirst conductive plate 11 in the first direction x, and is electricallyinsulated from the first conductive plate 11.

As shown in FIGS. 6, 7, and 10B, a second substrate 14, which haselectrical insulating properties, is bonded to the second conductiveplate 12. The second substrate 14 is located between the plurality ofsecond switching elements 22 and the output terminal 33 in the firstdirection x, and extends in the second direction y. The constituentmaterial of the second substrate 14 is the same as the constituentmaterial of the first substrate 13. The second substrate 14 is bonded,using an adhesive (not-shown), to the side of the second conductiveplate 12 that is opposite to the insulating layer 10 in the thicknessdirection z. A second gate layer 141 and a second detection layer 142are arranged on the second substrate 14. The second gate layer 141 andthe second detection layer 142 are electrically conductive, and extendin the second direction y. The second gate layer 141 and the seconddetection layer 142 are made of a Cu foil, for example. In the shownexample, the second gate layer 141 is adjacent to the output terminal 33in the first direction x. The second detection layer 142 is adjacent tothe plurality of second switching elements 22 in the first direction x.

As shown in FIGS. 6 to 11, the insulating material 15 is an electricallyinsulating member that is interposed between the first conductive plate11 and the second conductive plate 12 in the first direction x. Theinsulating material 15 is made of a material that has relatively highthermal conductivity, as with the insulating layer 10. The constituentmaterial of the insulating material 15 is, for example, a ceramic suchas Al₂O₃, Si₃N₄ (silicon nitride), or AlN.

The plurality of first switching elements 21 are semiconductor elements,and are electrically bonded to the first conductive plate 11, as shownin FIGS. 6 to 9 (that is, each first switching element 21 is fixed tothe first conductive plate 11 and is electrically connected to the firstconductive plate 11). Furthermore, the plurality of first switchingelements 21 are electrically connected to the second conductive plate12. The plurality of first switching elements 21 are bonded to the sideof the first conductive plate 11 that is opposite to the insulatinglayer 10 in the thickness direction z. In the semiconductor device A10,the first switching elements 21 are electrically connected to the secondconductive plate 12 via the first conductive wire 411. In thesemiconductor device A10, each of the plurality of first switchingelements 21 is a power MOSFET (Metal-Oxide-Semiconductor Field-EffectTransistor) whose main component is SiC (silicon carbide). The pluralityof first switching elements 21 each may also be an IGBT (Insulated GateBipolar Transistor). The plurality of first switching elements 21 arelined up in the second direction y. In the shown example, the number ofthe plurality of first switching elements 21 is four, but the number isnot limited to this. The first switching elements 21 each have a mainsurface 21A and a back surface 21B.

As shown in FIG. 9, the main surface 21A is oriented in the samedirection as that of the main surface 101 of the insulating layer 10.The main surface 21A is provided with a main surface electrode 211 and agate electrode 213 (see FIG. 12). The back surface 21B is orientedtoward the opposite side of the main surface 21A, and faces the firstconductive plate 11. The back surface 21B is provided with a backsurface electrode 212.

Source currents (or emitter currents if the first switching elements 21are IGBTs) flow through the main surface electrode 211. As shown in FIG.12, the main surface electrode 211 is divided into four regions providedon the main surface 21A. A configuration is such that a source currentflows through each of the regions.

A drain current (or a collector current if the first switching elements21 are IGBTs) flows through the back surface electrode 212. As shown inFIG. 9, the back surface electrode 212 is electrically connected to thefirst conductive plate 11 via an element joining layer 29.

A gate voltage for driving the first switching element 21 is applied tothe gate electrode 213. As shown in FIG. 12, in the semiconductor deviceA10, the gate electrode 213 is located between two regions of the mainsurface electrode 211 that are spaced apart from each other in the firstdirection x. The gate electrode 213 is smaller in size than all of theregions of the main surface electrode 211.

As shown in FIGS. 6, 7, 10B, and 11, the plurality of second switchingelements 22 are semiconductor elements electrically bonded to the secondconductive plate 12. The plurality of second switching elements 22 arebonded to the side of the second conductive plate 12 that is opposite tothe insulating layer 10 in the thickness direction z. The secondswitching elements 22 are electrically connected to the second supplyterminal 32 via the second conductive wires 421. The second switchingelements 22 are the same elements as the first switching elements 21.The plurality of second switching elements 22 are lined up in the seconddirection y. In the shown example, the number of the plurality of secondswitching elements 22 is four, but the number is not limited to this.The second switching elements 22 each have a main surface 22A and a backsurface 22B.

As shown in FIG. 11, the main surface 22A is oriented in the samedirection as that of the main surface 101 of the insulating layer 10.The main surface 22A is provided with a main surface electrode 221 and agate electrode 223 (see FIG. 13). The back surface 22B is orientedtoward a side opposite to the main surface 22A, and faces the secondconductive plate 12. The back surface 22B is provided with a backsurface electrode 222.

Source currents (or emitter currents if the second switching elements 22are IGBTs) flow through the main surface electrode 221. As shown in FIG.13, in the semiconductor device A10, the main surface electrode 221 isdivided into four regions provided on the main surface 22A. Aconfiguration is such that a source current flows through each of theregions.

A drain current (or a collector current if the second switching elements22 are IGBTs) flows through the back surface electrode 222. As shown inFIG. 11, the back surface electrode 222 is electrically connected to thesecond conductive plate 12 via an element joining layer 29.

A gate voltage for driving the second switching element 22 is applied tothe gate electrode 223. As shown in FIG. 13, in the semiconductor deviceA10, the gate electrode 223 is located between two regions of the mainsurface electrode 221 that are spaced apart from each other in the firstdirection x. The gate electrode 223 is smaller in size than all of theregions of the main surface electrode 221.

As shown in FIG. 9, the element joining layer 29 is interposed betweenthe back surface 21B of the first switching element 21 and the firstconductive plate 11. Furthermore, as shown in FIG. 11, the elementjoining layer 29 is interposed between the back surface 22B of thesecond switching element 22 and the second conductive plate 12. Theelement joining layers 29 are electrically conductive. The elementjoining layers 29 are lead-free solders whose main component is Sn(tin), for example. The first switching elements 21 are electricallybonded to the first conductive plate 11 through die bonding using theelement joining layers 29. Similarly, the second switching elements 22are bonded to the second conductive plate 12 through die bonding usingthe element joining layers 29.

As shown in FIGS. 3 to 7 (excluding FIG. 6), the first supply terminal31 is an electrically conductive member that is made of metal, isplate-shaped, and is electrically bonded to the first conductive plate11. The first supply terminal 31 serves as a positive electrode (Pterminal) of the semiconductor device A10. The constituent material ofthe first supply terminal 31 is Cu, for example. The surface of thefirst supply terminal 31 may also be plated with Ni (nickel). The firstsupply terminal 31 has a thickness set to 0.5 to 1.5 mm. The firstsupply terminal 31 has comb tooth-shaped portions 311 and an externalconnection portion 312 (see FIG. 7). The comb tooth-shaped portions 311are adjacent to the first substrate 13 in the first direction x, andoverlap with the first conductive plate 11 as viewed in a plan view. Thecomb tooth-shaped portions 311 are bonded to the side of the firstconductive plate 11 that is opposite to the insulating layer 10 in thethickness direction z. The method of joining the comb tooth-shapedportions 311 to the first conductive plate 11 may be solder joining orultrasonic joining. The external connection portion 312 is band-shapedand extends, from the comb tooth-shaped portions 311, to a side awayfrom the second conductive plate 12 in the first direction x. Theexternal connection portion 312 is partially exposed to the outside fromthe semiconductor device A10.

As shown in FIGS. 1 to 6, and 10A, the second supply terminal 32 is anelectrically conductive member that is made of metal, is plate-shaped,and has a region that overlaps with the first supply terminal 31 asviewed in a plan view. The second supply terminal 32 is spaced apartfrom all of the first conductive plate 11, the second conductive plate12, and the first supply terminal 31 in the thickness direction z (seeFIG. 10A). Accordingly, the second supply terminal 32 is electricallyinsulated from all of the first conductive plate 11, the secondconductive plate 12, and the first supply terminal 31. The second supplyterminal 32 is electrically connected to the plurality of secondswitching elements 22 (see FIG. 6). The second supply terminal 32 servesas a negative electrode (N terminal) of the semiconductor device A10.The constituent material and the thickness of the second supply terminal32 are the same as the constituent material and the thickness of thefirst supply terminal 31. The surface of the second supply terminal 32may also be plated with Ni. As shown in FIG. 6, the second supplyterminal 32 has a first band-shaped portion 321 (that extends in thesecond direction y), a plurality of second band-shaped portions 322 thatare parallel to each other (each second band-shaped portion extending inthe first direction x), and an external connection portion 323 (thatextends in the first direction x). The first band-shaped portion 321 andthe external connection portion 323 overlap with the first supplyterminal 31 as viewed in a plan view. The first band-shaped portion 321is located between a peripheral edge of the first conductive plate 11(peripheral edge that intersects with the first supply terminal 31), andthe first substrate 13. The plurality of second band-shaped portions 322extend from the first band-shaped portion 321 toward the secondconductive plate 12, and are lined up at a distance from each other inthe second direction y. In the shown example, the number of theplurality of second band-shaped portions 322 is four, but the number isnot limited to this. The external connection portion 323 is band-shapedand extends, from the first band-shaped portion 321, to a side away fromthe second conductive plate 12 in the first direction x. The externalconnection portion 323 is partially exposed to the outside from thesemiconductor device A10.

As shown in FIGS. 10A to 11, an insulator 324 is interposed between theleading end of the second band-shaped portion 322 of the second supplyterminal 32, and the first conductive plate 11. The insulator 324 is anelectrically-insulating adhesive. The constituent material of theinsulator 324 is, for example, an epoxy resin or polyimide. The secondband-shaped portions 322 are bonded to the first conductive plate 11 viathe insulators 324. Due to the insulators 324, the second supplyterminal 32 is bonded to the first conductive plate 11, and iselectrically insulated from the first conductive plate 11.

As shown in FIGS. 1 to 6, and 10A, the terminal insulating member 39 isplate-shaped, and is interposed between the first supply terminal 31 andthe second supply terminal 32 in the thickness direction z. The terminalinsulating member 39 has electrical insulating properties. Theconstituent material of the terminal insulating member 39 is a ceramicsuch as Al₂O₃, for example. The terminal insulating member 39 has athickness set to 0.1 to 1.0 mm. In the semiconductor device A10, theterminal insulating member 39 is in contact with both the first supplyterminal 31 and the second supply terminal 32. More specifically, theterminal insulating member 39 is in contact with the entire uppersurface of the first supply terminal 31 (see FIGS. 4 and 7), and is incontact with a part of the lower surface of the second supply terminal32 (that is, the entire lower surface of the external connection portion323 and a part of the lower surface of the first band-shaped portion321) (see FIGS. 4, 6, and 7). The plurality of second band-shapedportions 322 of the second supply terminal 32 are not in contact withthe terminal insulating member 39 (see FIG. 10A).

As shown in FIG. 6, (part of) every second band-shaped portion 322 ofthe second supply terminal 32 is located between two adjacent firstswitching elements 21. In other words, a corresponding single secondband-shaped portion 322 extends between two adjacent first switchingelements 21 toward the second conductive plate 12. Furthermore, each ofthe second switching elements 22 faces the corresponding single secondband-shaped portion 322 in the first direction x. Accordingly, theplurality of first switching elements 21 and the plurality of secondswitching elements 22 are staggered. In the shown example, the pluralityof first switching elements 21 are shifted, in the second direction y,with respect to the plurality of second switching elements 22.Furthermore, the first switching elements 21 are laid out withoutoverlapping with any second switching element 22 as viewed in the firstdirection x.

As shown in FIGS. 1 to 7, the output terminal 33 is an electricallyconductive member that is made of metal, is plate-shaped, and iselectrically bonded to the second conductive plate 12. Electric powerinput to the semiconductor device A10 from the first supply terminal 31and the second supply terminal 32 is converted by the plurality of firstswitching elements 21 and the plurality of second switching elements 22,and the converted power is output to the output terminal 33. Theconstituent material and the thickness of the output terminal 33 are thesame as the constituent material and the thickness of the first supplyterminal 31. The surface of the output terminal 33 may also be platedwith Ni. The output terminal 33 has comb tooth-shaped portions 331 andan external connection portion 332. The comb tooth-shaped portions 331are adjacent to the second substrate 14 in the first direction x, andoverlap with the second conductive plate 12 as viewed in a plan view.The comb tooth-shaped portions 331 are bonded to the side of the secondconductive plate 12 that is opposite to the insulating layer 10 in thethickness direction z. The method of joining the comb tooth-shapedportions 331 to the second conductive plate 12 may be solder joining orultrasonic joining. The external connection portion 332 is band-shapedand extends, from the comb tooth-shaped portions 331, to a side awayfrom the first conductive plate 11 in the first direction x. Therefore,the external connection portion 332 extends toward the side opposite tothe side to which the external connection portion 312 of the firstsupply terminal 31 and the external connection portion 323 of the secondsupply terminal 32 extend. The external connection portion 332 ispartially exposed to the outside from the semiconductor device A10.

As shown in e.g. FIG. 6, the semiconductor device A10 is provided with afirst gate terminal 341. The first gate terminal 341 is electricallyconductive, and is arranged opposing, in the second direction y, thefirst gate layer 131 while extending to a side away from the first gatelayer 131. The first gate terminal 341 is spaced apart from the firstconductive plate 11. Furthermore, as shown in FIGS. 2 and 3, the firstgate terminal 341 is partially exposed to the outside of thesemiconductor device A10. The constituent material of the first gateterminal 341 is, for example, Cu. The surface of the first gate terminal341 is plated with Sn.

As shown in e.g. FIG. 6, the semiconductor device A10 is provided with afirst terminal wire 451. The first terminal wire 451 is electricallyconductive, and connects the first gate terminal 341 and the first gatelayer 131. The constituent material of the first terminal wire 451 is,for example, Al (aluminum). The first gate terminal 341 is electricallyconnected to the first gate layer 131 via the first terminal wire 451.

As shown in FIG. 12 for example, the semiconductor device A10 isprovided with first gate wires 431. The first gate wires 431 areelectrically conductive, and connect the gate electrodes 213 of thefirst switching elements 21 and the first gate layer 131 to each other.The constituent material of the first gate wire 431 is Al, for example.The gate electrodes 213 are electrically connected to the first gatelayer 131 via the first gate wires 431. Accordingly, the first gateterminal 341 is electrically connected to the gate electrodes 213. Thesemiconductor device A10 has a configuration in which the plurality offirst switching elements 21 are driven upon application of a gatevoltage to the first gate terminal 341.

As shown in FIG. 7, the semiconductor device A10 is provided with asecond gate terminal 342. The second gate terminal 342 is electricallyconductive, and is arranged opposing, in the second direction y, thesecond gate layer 141 while extending to a side away from the secondgate layer 141. As shown in FIGS. 2 and 3, the second gate terminal 342is partially exposed to the outside of the semiconductor device A10. Theconstituent material of the second gate terminal 342 is the same as theconstituent material of the first gate terminal 341. The surface of thesecond gate terminal 342 is plated with Sn.

As shown in FIG. 7, the semiconductor device A10 is provided with asecond terminal wire 452. The second terminal wire 452 is electricallyconductive, and connects the second gate terminal 342 and the secondgate layer 141. The constituent material of the second terminal wire 452is the same as the constituent material of the first terminal wire 451.The second gate terminal 342 is electrically connected to the secondgate layer 141 via the second terminal wire 452.

As shown in FIGS. 7 and 13, the semiconductor device A10 is providedwith second gate wires 432. The second gate wires 432 are electricallyconductive, and connect the gate electrodes 223 of the second switchingelements 22 and the second gate layer 141. The constituent material ofthe second gate wires 432 is the same as the constituent material of thefirst gate wires 431. The gate electrodes 223 are electrically connectedto the second gate layer 141 via the second gate wires 432. Accordingly,the second gate terminal 342 is electrically connected to the gateelectrodes 223. In the semiconductor device A10, the plurality of secondswitching elements 22 are driven upon application of a gate voltage tothe second gate terminal 342.

As shown in FIG. 7, the semiconductor device A10 is provided with afirst detection terminal 351. The first detection terminal 351 iselectrically conductive, and is arranged opposing, in the seconddirection y, the first detection layer 132 while extending to a sideaway from the first detection layer 132. As shown in FIGS. 2 and 3, thefirst detection terminal 351 is partially exposed to the outside of thesemiconductor device A10. The first detection terminal 351 is spacedapart from the first gate terminal 341 in the first direction x. Theconstituent material of the first detection terminal 351 is the same asthe constituent material of the first gate terminal 341. The surface ofthe first detection terminal 351 is plated with Sn.

As shown in FIG. 7, the semiconductor device A10 is provided with athird terminal wire 453. The third terminal wire 453 is electricallyconductive, and connects the first detection terminal 351 and the firstdetection layer 132. The constituent material of the third terminal wire453 is the same as the constituent material of the first terminal wire451. The first detection terminal 351 is electrically connected to thefirst detection layer 132 via the third terminal wire 453.

As shown in FIGS. 7 and 12, the semiconductor device A10 is providedwith first detection wires 441. The first detection wires 441 areelectrically conductive, and connect the main surface electrodes 211 ofthe first switching elements 21 and the first detection layer 132. Theconstituent material of the first detection wires 441 is, for example,Al. Each first detection wire 441 is connected to one of the regions ofthe corresponding main surface electrode 211. The main surfaceelectrodes 211 are electrically connected to the first detection layer132 via the first detection wires 441. Accordingly, the first detectionterminal 351 is electrically connected to the main surface electrodes211. In the semiconductor device A10, a source current (or emittercurrent) that is input to the plurality of first switching elements 21is detected by the first detection terminal 351.

As shown in FIG. 7, the semiconductor device A10 is provided with asecond detection terminal 352. The second detection terminal 352 iselectrically conductive, and is arranged opposing, in the seconddirection y, the second detection layer 142 while extending to a sideaway from the second detection layer 142. As shown in FIGS. 2 and 3, thesecond detection terminal 352 is partially exposed to the outside of thesemiconductor device A10. The second detection terminal 352 is spacedapart from the second gate terminal 342 in the first direction x. Theconstituent material of the second detection terminal 352 is the same asthe constituent material of the first gate terminal 341. The surface ofthe second detection terminal 352 is plated with Sn.

As shown in FIG. 7, the semiconductor device A10 is provided with afourth terminal wire 454. The fourth terminal wire 454 is electricallyconductive, and connects the second detection terminal 352 and thesecond detection layer 142. The constituent material of the fourthterminal wire 454 is the same as the constituent material of the firstterminal wire 451. The second detection terminal 352 is electricallyconnected to the second detection layer 142 via the fourth terminal wire454.

As shown in FIGS. 7 and 13, the semiconductor device A10 is providedwith second detection wires 442. The second detection wires 442 areelectrically conductive, and connect the main surface electrodes 221 ofthe second switching elements 22 and the second detection layer 142. Theconstituent material of the second detection wires 442 is the same asthe constituent material of the first detection wires 441. Each seconddetection wire 442 is connected to one of the regions of thecorresponding main surface electrode 221. The main surface electrodes221 are electrically connected to the second detection layer 142 via thesecond detection wires 442. Accordingly, the second detection terminal352 is electrically connected to the main surface electrodes 221. In thesemiconductor device A10, a source current (or a drain current) that isinput to the plurality of second switching elements 22 is detected bythe second detection terminal 352.

As shown in FIG. 7, the semiconductor device A10 is provided with adevice current detection terminal 36. The device current detectionterminal 36 is electrically conductive, and is arranged between thefirst detection terminal 351 and the second detection terminal 352 inthe first direction x, and is arranged opposing the first conductiveplate 11 in the second direction y. The device current detectionterminal 36 extends to a side away from the first conductive plate 11 inthe second direction y. As shown in FIGS. 2 and 3, the device currentdetection terminal 36 is partially exposed to the outside of thesemiconductor device A10. The constituent material of the device currentdetection terminal 36 is the same as the constituent material of thefirst gate terminal 341. The surface of the device current detectionterminal 36 is plated with Sn.

As shown in FIG. 7, the semiconductor device A10 is provided with afifth terminal wire 455. The fifth terminal wire 455 is electricallyconductive, and connects the device current detection terminal 36 andthe first conductive plate 11. The constituent material of the fifthterminal wire 455 is the same as the constituent material of the firstterminal wire 451. The device current detection terminal 36 iselectrically connected to the first conductive plate 11 via the fifthterminal wire 455. In the semiconductor device A10, a current that flowsthrough the first conductive plate 11 is detected by the device currentdetection terminal 36.

As shown in FIGS. 6 to 9, the first conductive wires 411 areelectrically conductive members that connect the main surface electrodes211 of the first switching elements 21 and the second conductive plate12. The first conductive wires 411 are thin metal wires that extend inthe first direction x. The first conductive wires 411 are connected tothe respective regions of the main surface electrodes 211. In thesemiconductor device A10, the plurality of first switching elements 21are electrically connected to the second conductive plate 12 via thefirst conductive wires 411. The constituent material of the firstconductive wires 411 is, for example, Al.

As shown in FIGS. 6 to 11 (excluding FIGS. 8 and 9), the secondconductive wires 421 are electrically conductive members that connectthe second band-shaped portions 322 of the second supply terminal 32 andthe main surface electrodes 221 of the second switching elements 22. Thesecond conductive wires 421 are thin metal wires that extend in thefirst direction x. The second conductive wires 421 are connected to therespective regions of the main surface electrodes 221. In thesemiconductor device A10, the second band-shaped portions 322 areelectrically connected to the main surface electrodes 221 via the secondconductive wires 421. The constituent material of the second conductivewires 421 is the same as the constituent material of the firstconductive wires 411.

As shown in FIGS. 1 to 11 (excluding FIGS. 6 and 7), the sealing resin50 covers the first conductive plate 11, the second conductive plate 12,the plurality of first switching elements 21, and the plurality ofsecond switching elements 22. The sealing resin 50 has electricalinsulating properties. The constituent material of the sealing resin 50is, for example, a black epoxy resin. The sealing resin 50 has a frontsurface 51, a back surface 52, a pair of first side surfaces 531, and apair of second side surfaces 532.

As shown in FIGS. 1 to 11 (excluding FIGS. 3, 6, and 7), the frontsurface 51 is oriented in the same direction as that of the main surface101 of the insulating layer 10. As shown in FIGS. 3 to 11 (excludingFIGS. 6 and 7), the back surface 52 is oriented in the same direction asthat of the back surface 102 of the insulating layer 10. The backsurface 102 is exposed from the back surface 52.

As shown in FIGS. 1 to 5, each of the pair of first side surfaces 531 isconnected to both the front surface 51 and the back surface 52, and arespaced apart from each other in the first direction x. The externalconnection portion 312 of the first supply terminal 31, the externalconnection portion 323 of the second supply terminal 32, and theterminal insulating member 39 are partially exposed from one of thefirst side surfaces 531. Furthermore, the external connection portion332 of the output terminal 33 is partially exposed from the other one ofthe first side surfaces 531. As shown in FIGS. 1 to 5, each of the pairof second side surfaces 532 is connected to both the front surface 51and the back surface 52, and are spaced apart from each other in thesecond direction y. Both ends, in the first direction x, of each secondside surface 532 are connected to the pair of first side surfaces 531.The first gate terminal 341, the second gate terminal 342, the firstdetection terminal 351, the second detection terminal 352, and thedevice current detection terminal 36 are partially exposed from one ofthe second side surfaces 532.

As shown in FIGS. 1, 3, 4, 10A, and 10B, the sealing resin 50 isprovided with a plurality of grooves 54 that are recessed from the backsurface 52 in the thickness direction z, and extend in the seconddirection y. The plurality of grooves 54 are located at both ends, inthe first direction x, of the back surface 52. For example, in theexample shown in FIG. 3, the plurality of grooves 54 are classified intoa first group of grooves (for example, a right-side group of grooves)and a second group of grooves (a left-side group of grooves), and thetwo groups are spaced apart from each other in the first direction x. Inthe shown example, the right-side group of grooves is arranged in thevicinity of the right end of the back surface 52, and the left-sidegroup of grooves is arranged in the vicinity of the left end of the backsurface 52. Also, both groups of grooves 54 extend continuously from oneof the second side surfaces 532 to the other one of the second sidesurfaces 532.

The following will describe a circuit configuration of the semiconductordevice A10 with reference to FIG. 14. As shown in the figure, in thesemiconductor device A10, two switching circuits, namely, an upper armcircuit 71 and a lower arm circuit 72, are configured. These circuitsconstitute a DC-AC converter (inverter), which is a constituentcomponent of a DC-DC converter. The upper arm circuit 71 is constitutedby the first conductive plate 11 and the plurality of first switchingelements 21. In the upper arm circuit 71, the plurality of firstswitching elements 21 are connected in parallel to each other betweenthe first supply terminal 31 and the output terminal 33. All of the gateelectrodes 213 provided on the first switching elements 21 are connectedin parallel to the first gate terminal 341. Using a drive circuit suchas a gate driver arranged outside the semiconductor device A10, theplurality of first switching elements 21 are driven at the same timeupon application of a gate voltage to the first gate terminal 341.

Furthermore, all of the main surface electrodes 211 mounted on the firstswitching elements 21 are connected in parallel to the first detectionterminal 351. A source current (or emitter current) flowing through theplurality of first switching elements 21 is input to a control circuitarranged outside the semiconductor device A10 via the first detectionterminal 351.

The back surface electrodes 212 of the first switching elements 21 areconnected in parallel to the device current detection terminal 36. Adrain current (or a collector current) that flows through the pluralityof first switching elements 21, that is, a current that flows throughthe first conductive plate 11, is input to the control circuit arrangedoutside the semiconductor device A10 via the device current detectionterminal 36.

The lower arm circuit 72 is constituted by the second conductive plate12 and the plurality of second switching elements 22. In the lower armcircuit 72, the plurality of second switching elements 22 are connectedin parallel to each other between the output terminal 33 and the secondsupply terminal 32. All of the gate electrodes 223 provided on thesecond switching elements 22 are connected in parallel to the secondgate terminal 342. Using the drive circuit such as a gate driverarranged outside the semiconductor device A10, the plurality of secondswitching elements 22 are driven at the same time upon application of agate voltage to the second gate terminal 342.

Furthermore, all of the main surface electrodes 221 provided on thesecond switching elements 22 are connected in parallel to the seconddetection terminal 352. A source current (or emitter current) that flowsthrough the plurality of second switching elements 22 is input to thecontrol circuit arranged outside the semiconductor device A10 via thesecond detection terminal 352.

As a result of a DC power source being connected to the first supplyterminal 31 and the second supply terminal 32 and the plurality of firstswitching elements 21 and the plurality of second switching elements 22being driven, an AC voltage is output from output terminal 33. In, forexample, a boost DC-DC converter, the AC voltage is applied across avoltage inverter, a rectifier, and a smoothing circuit in the statedorder, and thus is converted into high-voltage DC power that is higherin voltage than the voltage of the DC power source.

The following will describe an example of usage of the semiconductordevice A10 with reference to FIG. 15. This figure is a schematic viewillustrating an electric automobile B that uses the semiconductor deviceA10. The electric automobile B is provided with a DC-DC converter 81, anon-board battery charger 82, a storage battery 83, and a driving system84. The semiconductor device A10 constitutes part of the DC-DC converter81 (DC-AC converter). If the electric automobile B is placed outdoorsand is supplied with DC power from a rapid power feeding facility 80,which is a DC power source, the DC power is converted into high-voltageDC power by the DC-DC converter 81. The DC-DC converter 81 supplies thehigh-voltage DC power to the storage battery 83. At the same time, poweris supplied from the on-board battery charger 82 to the storage battery83. The on-board battery charger 82 accumulates power supplied from anormal power feeding facility arranged outdoors. The on-board batterycharger 82 converts the power into high-voltage DC power and suppliesthe converted power to the storage battery 83. The storage battery 83can be charged in a short period of time since the storage battery 83 issupplied with high-voltage DC power from the two systems, namely, theDC-DC converter 81 and the on-board battery charger 82 at the same time.The power accumulated in the storage battery 83 is supplied to thedriving system 84 constituted by an inverter, an AC motor, and atransmission. The electric automobile B is driven by the driving system84.

The following will describe the functions and effects of thesemiconductor device A10. According to the configuration of thesemiconductor device A10, the first conductive plate 11 and the secondconductive plate 12 function as heat dissipation members andelectrically conductive members in the semiconductor device A10.Furthermore, the thickness t1 of the first conductive plate 11 and thethickness t2 of the second conductive plate 12 are larger than thethickness t0 of the insulating layer 10 on which these plates aremounted. Accordingly, in the first direction x and the second directiony, which are perpendicular to the thickness direction z, thecross-sectional areas of the first conductive plate 11 and the secondconductive plate 12 are larger than the cross-sectional area of aconductive layer made of, for example, a metal foil. Accordingly, in thefirst direction x and the second direction y, the thermal resistancesper unit length of the first conductive plate 11 and the secondconductive plate 12 are lower than the thermal resistance per unitlength of a conductive layer made of a metal foil. In other words, inthe first direction x and the second direction y, heat is more likely tobe transferred over a wide range through the first conductive plate 11and the second conductive plate 12 than a conductive layer made of ametal foil. Therefore, with the semiconductor device A10, it is possibleto improve the heat dissipation.

With the improvement in the heat dissipation of the semiconductor deviceA10, it is possible to reduce the electric resistance of the firstconductive plate 11 and the second conductive plate 12. Therefore, withthe semiconductor device A10, it is possible to suppress power loss.

It is preferable that the thickness t1 of the first conductive plate 11and the thickness t2 of the second conductive plate 12 be 1.5 to 10 mm,in order to reduce the thermal resistance per unit length in the firstdirection x and the second direction y. Alternatively, it is preferablethat the thickness t1 of the first conductive plate 11 and the thicknesst2 of the second conductive plate 12 be three to one thousand times aslarge as the thickness t0 of the insulating layer 10, in order to reducethe thermal resistance per unit length in the first direction x and thesecond direction y.

The semiconductor device A10 is provided with the insulating material 15that has electrical insulating properties, and is interposed between thefirst conductive plate 11 and the second conductive plate 12 in thefirst direction x. Accordingly, heat is transferred to the insulatingmaterial 15, a large heat transfer path is secured, and thus it ispossible to reduce a deviation between the thermal distribution of thefirst conductive plate 11 and the thermal distribution of the secondconductive plate 12. In view of the circuit configuration of thesemiconductor device A10, the first conductive plate 11, whichconstitutes the upper arm circuit 71, has a higher temperature than thatof the second conductive plate 12, which constitutes the lower armcircuit 72. Accordingly, by providing the insulating material 15, it ispossible to transfer the heat of the first conductive plate 11 to thesecond conductive plate 12.

The first band-shaped portion 321 and the plurality of secondband-shaped portions 322 of the second supply terminal 32 overlap withthe first conductive plate 11, as viewed in a plan view. Furthermore,the second band-shaped portions 322 are electrically connected to themain surface electrodes 221 of the second switching elements 22 via thesecond conductive wires 421, which extend in the first direction x.Accordingly, it is possible to suppress an increase in size of thesemiconductor device A10 as viewed in a plan view.

The plurality of second switching elements 22 are lined up in the seconddirection y, and each of the second switching elements 22 faces thecorresponding single second band-shaped portion 322 in the firstdirection x. Accordingly, it is possible to shorten the electricalconnect ion paths from the plurality of second switching elements 22 tothe second supply terminal 32, while suppressing an increase in size, inthe second direction y, of the semiconductor device A10. In this case,the plurality of first switching elements 21 are lined up in the seconddirection y, and part of each of the second band-shaped portions 322 islocated between two adjacent first switching elements 21. Accordingly,it is possible to further suppress an increase in size, in the seconddirection y, of the semiconductor device A10.

The semiconductor device A10 is provided with the second conductivewires 421, which are connected to the second band-shaped portions 322 ofthe second supply terminal 32 and the main surface electrodes 221 of thesecond switching elements 22 and extend in the first direction x.Accordingly, the conductive paths from the plurality of second switchingelements 22 to the second supply terminal 32 extend in the firstdirection x. Also, the semiconductor device A10 is provided with thefirst conductive wires 411, which are connected to the first switchingelements 21 and the second conductive plate 12 and extend in the firstdirection x. Accordingly, the conductive paths from the plurality offirst switching elements 21 to the second conductive plate 12 extend inthe first direction x. Accordingly, the conductive paths extending inthe first direction x are configured in the semiconductor device A10,and thus it is possible to improve the dielectric strength voltage ofthe semiconductor device A10.

The second band-shaped portions 322 of the second supply terminal 32 arebonded to the first conductive plate 11 via the insulators 324, whichhave electrical insulating properties. With this, the second supplyterminal 32 can be supported on the first conductive plate 11.Furthermore, when the second conductive wires 421 are bonded to thesecond band-shaped portions 322 using wire bonding, the secondband-shaped portions 322 are subjected to a reactive force exerted fromthe first conductive plate 11, thus making it possible to sufficientlyensure the joining strength between the second conductive wires 421 andthe second band-shaped portions 322.

The first substrate 13, which has electrical insulating properties, isbonded to the first conductive plate 11. The first substrate 13 isprovided with the first gate layer 131, which is electrically connectedto both the gate electrodes 213 of the first switching elements 21 andthe first gate terminal 341. Furthermore, the first gate terminal 341,which is electrically connected to the first gate layer 131, is spacedapart from the first conductive plate 11. Accordingly, in thesemiconductor device A10, a conductive path for driving the plurality offirst switching elements 21 can be configured with the first gate layer131 electrically insulated from the first conductive plate 11.

The second substrate 14, which has electrical insulating properties, isbonded to the second conductive plate 12. The second substrate 14 isprovided with the second gate layer 141, which is electrically connectedto both the gate electrodes 223 of the second switching elements 22 andthe second gate terminal 342. Furthermore, the second gate terminal 342,which is electrically connected to the second gate layer 141, is spacedapart from the second conductive plate 12. Accordingly, in thesemiconductor device A10, a conductive path for driving the plurality ofsecond switching elements 22 can be configured with the second gatelayer 141 electrically insulated from the second conductive plate 12.

The semiconductor device A10 includes the sealing resin 50, which coversthe first conductive plate 11, the second conductive plate 12, and thelike. The first supply terminal 31 and the second supply terminal 32have portions that extend to a side away from the second conductiveplate 12 in the first direction x, and are exposed from the sealingresin 50. Furthermore, the semiconductor device A10 is provided with theoutput terminal 33, which is electrically bonded to the secondconductive plate 12. The output terminal 33 has a portion that extendsto a side away from the first conductive plate 11 in the first directionx, and is exposed from the sealing resin 50. Accordingly, the firstsupply terminal 31 and the second supply terminal 32 are spaced apartfrom the output terminal 33 in the first direction x, which is the samedirection as that of the conductive path of the semiconductor deviceA10. This can further improve the dielectric strength voltage of thesemiconductor device A10.

A semiconductor device A20 according to a second embodiment of the firstaspect will be described with reference to FIGS. 16 to 20. In thesefigures, the same reference numerals are given to the same or similarcomponents as those in the above-described semiconductor device A10, andredundant descriptions thereof are omitted as appropriate. Furthermore,in FIG. 16 out of these figures, the sealing resin 50 is transparent,for convenience of understanding.

The semiconductor device A20 differs from the above-describedsemiconductor device A10 in that first electrical connection leads 412are provided in place of the first conductive wires 411, and secondelectrical connection leads 422 are provided in place of the secondconductive wires 421.

As shown in FIGS. 16 to 18, the first electrical connection leads 412are electrically conductive members that connect the main surfaceelectrodes 211 of the first switching elements 21 and the secondconductive plate 12. The first electrical connection leads 412 are metalplates that are band-shaped and extend in the first direction x, and arebent into a hook shape in the thickness direction z. The constituentmaterial of the first electrical connection leads 412 is Cu or a Cualloy. One end of each first electrical connection lead 412 iselectrically bonded to a main surface electrode 211 via a conductivejoint layer 49. The other end of the first electrical connection lead412 is electrically bonded to the second conductive plate 12 via aconductive joint layer 49. The conductive joint layers 49 areelectrically conductive. The conductive joint layers 49 are lead-freesolder whose main component is Sn, for example.

As shown in FIGS. 16, 19, and 20, the second electrical connection leads422 are electrically conductive members that connect the secondband-shaped portions 322 of the second supply terminal 32 and the mainsurface electrodes 221 of the second switching elements 22. The secondelectrical connection leads 422 are metal plates that are band-shapedand extend in the first direction x, and are bent into a hook shape inthe thickness direction z. The constituent material of the secondelectrical connection leads 422 is the same as the constituent materialof the first electrical connection leads 412. One end of each secondelectrical connection lead 422 is electrically bonded to a secondband-shaped portion 322 via a conductive joint layer 49. The other endof the second electrical connection lead 422 is electrically bonded to amain surface electrode 221 via a conductive joint layer 49.

The following will describe the functions and effects of thesemiconductor device A20. According to the configuration of thesemiconductor device A20, the same insulating layer 10, first conductiveplate 11, and second conductive plate 12 as those of the above-describedsemiconductor device A10 are provided. Accordingly, the first conductiveplate 11 and the second conductive plate 12 function as heat dissipationmembers and electrically conductive members in the semiconductor deviceA20. Therefore, also with the semiconductor device A20, it is possibleto improve the heat dissipation.

The semiconductor device A20 is provided with the first electricalconnection leads 412 in place of the first conductive wires 411, and thesecond electrical connection leads 422 in place of the second conductivewires 421. The cross-sectional areas of the first electrical connectionleads 412 and the second electrical connection leads 422 are larger thanthe cross-sectional areas of the first conductive wires 411 and thesecond conductive wires 421. Accordingly, the electric resistance of thefirst electrical connection leads 412 and the second electricalconnection leads 422 is lower than the electric resistance of the firstconductive wires 411 and the second conductive wires 421. Accordingly,it is possible to suppress power loss of the semiconductor device A20,compared to that of the semiconductor device A10.

A semiconductor device A30 according to a third embodiment of the firstaspect will be described with reference to FIGS. 21 to 23. In thesefigures, the same reference numerals are given to the same or similarcomponents as those in the above-described semiconductor device A10, anddescriptions thereof are omitted. Furthermore, in FIG. 21 out of thesefigures, the sealing resin 50 is transparent, for convenience ofunderstanding.

The semiconductor device A30 differs from the above-describedsemiconductor device A10 in that the first electrical connection leads412 are provided in place of the first conductive wires 411, and differsin the configuration of the second band-shaped portions 322 of thesecond supply terminal 32. Note that the configuration of the firstelectrical connection leads 412 is the same as that of the firstelectrical connection leads 412 of the above-described semiconductordevice A20, and thus a description thereof is omitted.

As shown in FIG. 21, the leading ends of the second band-shaped portions322 of the second supply terminal 32 extend to positions at which theyoverlap with the main surface electrodes 221 of the second switchingelements 22, as viewed in a plan view. As shown in FIGS. 22 and 23, theleading end of the second band-shaped portion 322 is bent into a hookshape in the thickness direction z. The leading end of each secondband-shaped portion 322 is electrically bonded to a main surfaceelectrode 211 via a conductive joint layer 49. Accordingly, the mainsurface electrodes 221 are electrically connected to the second supplyterminal 32 without using any of the second conductive wires 421 and thesecond electrical connection leads 422. Note that, in the semiconductordevice A30, since the second band-shaped portions 322 are not bonded tothe first conductive plate 11, there is no need to provide theinsulators 324.

The following will describe the functions and effects of thesemiconductor device A30. According to the configuration of thesemiconductor device A30, the same insulating layer 10, first conductiveplate 11, and second conductive plate 12 as those of the above-describedsemiconductor device A10 are provided. Accordingly, the first conductiveplate 11 and the second conductive plate 12 function as heat dissipationmembers and electrically conductive members in the semiconductor deviceA30. Therefore, also with the semiconductor device A30, it is possibleto improve the heat dissipation.

The second band-shaped portions 322 of the second supply terminal 32 areconnected to the main surface electrodes 221 of the second switchingelements 22. Accordingly, in the semiconductor device A30, there is noneed to provide any of the second conductive wires 421, the secondelectrical connection leads 422, and the insulators 324. It is thuspossible to reduce the number of components needed to manufacture thesemiconductor device A30.

A semiconductor device A40 according to a fourth embodiment of the firstaspect will be described with reference to FIGS. 24 to 29. In thesefigures, the same reference numerals are given to the same or similarcomponents as those in the above-described semiconductor device A10, andredundant descriptions thereof are omitted. Furthermore, in FIG. 24 outof these figures, the sealing resin 50 is transparent, for convenienceof understanding.

The semiconductor device A40 differs from the above-describedsemiconductor device A10 in that it is provided with a metal layer 16and a heat radiator 60. As shown in FIG. 29, the metal layer 16 is aconductive layer bonded to the back surface 102 of the insulating layer10. The constituent material of the metal layer 16 is Cu. The metallayer 16 has a thickness t3 set to 0.25 to 0.8 mm. Accordingly, thethickness t3 of the metal layer 16 is smaller than the thickness t1 ofthe first conductive plate 11 and the thickness t2 of the secondconductive plate 12. The metal layer 16 is electrically insulated fromthe first conductive plate 11 and the second conductive plate 12 by theinsulating layer 10.

As shown in FIGS. 24 to 29, the heat radiator 60 is bonded to the metallayer 16. In the semiconductor device A40, the heat radiator 60 is plateshaped, but the shape of the heat radiator 60 is not limited. The heatradiator 60 is exposed to the outside of the semiconductor device A40.

As shown in FIG. 24, the semiconductor device A40 is provided with thefirst conductive wires 411 and the second conductive wires 421, as inthe semiconductor device A10. The semiconductor device A40 may also havea configuration in which the first electrical connection leads 412 andthe second electrical connection leads 422 are provided in place of thefirst conductive wires 411 and the second conductive wires 421, as inthe semiconductor device A20. Furthermore, the semiconductor device A40may also have a configuration in which the first electrical connectionleads 412 are provided and the second band-shaped portions 322 of thesecond supply terminal 32 are connected to the main surface electrodes221 of the second switching elements 22, as in the semiconductor deviceA30.

The following will describe the functions and effects of thesemiconductor device A40. According to the configuration of thesemiconductor device A40, the same insulating layer 10, first conductiveplate 11, and second conductive plate 12 as those of the above-describedsemiconductor device A10 are provided. Accordingly, the first conductiveplate 11 and the second conductive plate 12 function as heat dissipationmembers and electrically conductive members in the semiconductor deviceA40. Therefore, also with the semiconductor device A40, it is possibleto improve the heat dissipation.

The semiconductor device A40 is provided with the heat radiator 60.Accordingly, it is possible to further improve the heat dissipation ofthe semiconductor device A40. Furthermore, by providing the metal layer16, it is possible to easily join the heat radiator 60 to the metallayer 16 using, for example, a solder or the like.

A semiconductor device A50 according to a fifth embodiment of the firstaspect will be described with reference to FIGS. 30 to 32. In thesefigures, the same reference numerals are given to the same or similarcomponents as those in the above-described semiconductor device A10, andredundant descriptions thereof are omitted. Furthermore, in FIG. 30 outof these figures, the sealing resin 50 is transparent, for convenienceof understanding.

The semiconductor device A50 differs from the above-describedsemiconductor device A10 in that it is provided with the metal layer 16and the heat radiator 60, and differs in configurations of the firstconductive plate 11 and the second conductive plate 12. Note that theconfigurations of the metal layer 16 and the heat radiator 60 are thesame as those of the above-described semiconductor device A40, and thusa description thereof is omitted.

As shown in FIGS. 31A to 32, the first conductive plate 11 has a firstlayer 111 and a second layer 112. The first layer 111 is bonded to themain surface 101 of the insulating layer 10. The second layer 112 islocated on a side of the first layer 111 that is opposite to theinsulating layer 10 in the thickness direction z, and is bonded to thefirst layer 111 with a conductive joint layer 49. The constituentmaterial of both the first layer 111 and the second layer 112 is Cu. Thefirst layer 111 has a thickness set to 0.25 to 0.8 mm. The second layer112 has a thickness that is equal to or larger than 2.0 mm, and islarger than the thickness of the first layer 111. The semiconductordevice A50 is configured such that the thickness t1 of the firstconductive plate 11 is obtained by adding the thickness of theconductive joint layer 49 to the thicknesses of the first layer 111 andthe second layer 112.

As shown in FIGS. 31A to 32, the second conductive plate 12 has a firstlayer 121 and a second layer 122. The first layer 121 is bonded to themain surface 101 of the insulating layer 10. The second layer 122 islocated on a side of the first layer 121 that is opposite to theinsulating layer 10 in the thickness direction z, and is bonded to thefirst layer 121 with a conductive joint layer 49. The constituentmaterial of both the first layer 121 and the second layer 122 is Cu. Thefirst layer 121 has a thickness that is equal to the thickness of thefirst layer 111 of the first conductive plate 11. The second layer 122has a thickness that is equal to the thickness of the second layer 112of the first conductive plate 11. Accordingly, the thickness of thesecond layer 122 is larger than the thickness of the first layer 121.The semiconductor device A50 is configured such that the thickness t2 ofthe second conductive plate 12 is obtained by adding the thickness ofthe conductive joint layer 49 to the thicknesses of the first layer 121and the second layer 122.

As shown in FIG. 30, the semiconductor device A50 is provided with thefirst conductive wires 411 and the second conductive wires 421, as inthe semiconductor device A10. The semiconductor device A50 may also havea configuration in which the first electrical connection leads 412 andthe second electrical connection leads 422 are provided in place of thefirst conductive wires 411 and the second conductive wires 421, as inthe semiconductor device A20. Furthermore, the semiconductor device A50may also have a configuration in which the first electrical connectionleads 412 are provided and the second band-shaped portions 322 of thesecond supply terminal 32 are connected to the main surface electrodes221 of the second switching elements 22, as in the semiconductor deviceA30.

The following will describe the functions and effects of thesemiconductor device A50. According to the configuration of thesemiconductor device A50, the same insulating layer 10, first conductiveplate 11, and second conductive plate 12 as those of the above-describedsemiconductor device A10 are provided. Accordingly, the first conductiveplate 11 and the second conductive plate 12 function as heat dissipationmembers and electrically conductive members in the semiconductor deviceA50. Therefore, also with the semiconductor device A50, it is possibleto improve the heat dissipation.

The first conductive plate 11 has the first layer 111 and the secondlayer 112, and the thickness of the second layer 112 is larger than thethickness of the first layer 111. Furthermore, the second conductiveplate 12 has the first layer 121 and the second layer 122, and thethickness of the second layer 122 is larger than the thickness of thefirst layer 121. This means that the insulating layer 10, the firstconductive plate 11, the second conductive plate 12, and the metal layer16 can be easily configured, by joining a metal plate to a metal foillayer provided on one side of an existing patterned DBC (Direct BondingCopper: registered trademark) substrate using the conductive jointlayers 49.

In the present invention, a plurality of diodes (such as schottkybarrier diodes) constituting parallel circuits that correspond to thefirst switching elements 21 may also be electrically bonded to the firstconductive plate 11. Furthermore, a plurality of diodes constitutingparallel circuits that correspond to the second switching elements 22may also be electrically bonded to the second conductive plate 12. Byproviding the plurality of diodes, it is possible to avoid, when theplurality of first switching elements 21 are driven, the generation of areverse current from flowing through the first switching elements 21even if a back electromotive force is generated by the switching.Similarly, it is also possible to avoid, when the plurality of secondswitching elements 22 are driven, the generation of a reverse currentfrom flowing through the second switching elements 22.

The above-described various embodiments of the first aspect can bedefined, for example, as the following Clauses.

Clause 1. A semiconductor device comprising:

an insulating layer that has a main surface oriented in a thicknessdirection;

a first conductive plate and a second conductive plate that are bondedto the main surface, and are spaced apart from each other in a firstdirection which is perpendicular to the thickness direction;

a plurality of first switching elements that are electrically bonded tothe first conductive plate and are electrically connected to the secondconductive plate;

a plurality of second switching elements that are electrically bonded tothe second conductive plate;

a first supply terminal that is electrically bonded to the firstconductive plate; and

a second supply terminal that is spaced apart from both the firstconductive plate and the first supply terminal in the thicknessdirection, and is electrically connected to the plurality of secondswitching elements,

wherein the first conductive plate and the second conductive plate havea thickness that is larger than a thickness of the insulating layer.

Clause 2. The semiconductor device according to Clause 1, wherein thethickness of the first conductive plate and the second conductive plateis 1.5 to 10 mm.

Clause 3. The semiconductor device according to Clause 1, wherein thethickness of the first conductive plate and the second conductive plateis three to one hundred times as large as the thickness of theinsulating layer.

Clause 4. The semiconductor device according to Clause 2 or 3, whereinthe first conductive plate and the second conductive plate are made of amaterial that contains Cu.

Clause 5. The semiconductor device according to any one of Clauses 2 to4, further comprising an insulating material that is interposed betweenthe first conductive plate and the second conductive plate in the firstdirection.

Clause 6. The semiconductor device according to any one of Clauses 2 to5, wherein each of the plurality of second switching elements has anelement main surface on which a main surface electrode is provided,

the second supply terminal includes a first band-shaped portion thatextends in a second direction which is perpendicular to both thethickness direction and the first direction, and a plurality of secondband-shaped portions that extend from the first band-shaped portiontoward the second conductive plate, and are spaced apart from each otherin the second direction, and

the plurality of second band-shaped portions are electrically connectedto the main surface electrodes of the plurality of second switchingelements.

Clause 7. The semiconductor device according to Clause 6, furthercomprising a plurality of conductive wires that are connected to theplurality of second band-shaped portions and the main surface electrodesof the plurality of second switching elements,

wherein the plurality of conductive wires extend in the first direction.

Clause 8. The semiconductor device according to Clause 6, furthercomprising a plurality of electrical connection leads that are connectedto the plurality of second band-shaped portions and the main surfaceelectrodes of the plurality of second switching elements,

wherein the plurality of electrical connection leads extend in the firstdirection.

Clause 9. The semiconductor device according to Clause 7 or 8, whereineach of the plurality of second band-shaped portions is bonded to thefirst conductive plate via an insulator.

Clause 10. The semiconductor device according to Clause 6, wherein theplurality of second band-shaped portions are bonded to the main surfaceelectrodes of the plurality of second switching elements.

Clause 11. The semiconductor device according to Clause 10, wherein theplurality of second switching elements are spaced apart from each otherin the second direction, and

the plurality of second switching elements respectively face theplurality of second band-shaped portions in the first direction.

Clause 12. The semiconductor device according to Clause 11, furthercomprising: a substrate; a gate layer; and a gate terminal, wherein thesubstrate extends in the second direction, has an electrical insulatingproperty, and is bonded to the second conductive plate,

the gate layer extends in the second direction, is electricallyconductive, and is arranged on the substrate,

the gate terminal is spaced apart from the second conductive plate, andis electrically connected to the gate layer, and

the element main surface of each of the plurality of second switchingelements is provided with a gate electrode that is spaced apart from themain surface electrode and is electrically connected to the gate layer.

Clause 13. The semiconductor device according to any one of Clauses 2 to12, further comprising a metal layer that is bonded to the insulatinglayer,

wherein the insulating layer has a back surface that is oriented towarda side opposite to the main surface, and the metal layer is bonded tothe back surface of the insulating layer, and

the metal layer has a thickness that is smaller than the thickness ofthe first conductive plate and the second conductive plate.

Clause 14. The semiconductor device according to Clause 13, wherein eachof the first conductive plate and the second conductive plate includes afirst layer that is bonded to the main surface of the insulating layer,and a second layer that is located on a side of the first layer that isopposite to the insulating layer in the thickness direction, and thesecond layer has a thickness that is larger than a thickness of thefirst layer.

Clause 15. The semiconductor device according to Clause 13 or 14,further comprising a heat radiator that is bonded to the metal layer.

Clause 16. The semiconductor device according to any one of Clauses 2 to15, further comprising a sealing resin that covers the first conductiveplate, the second conductive plate, the plurality of first switchingelements, and the plurality of second switching elements,

wherein the first supply terminal and the second supply terminal eachhave a portion that extends to a side away from the second conductiveplate in the first direction and is exposed from the sealing resin.

Clause 17. The semiconductor device according to Clause 16, furthercomprising an output terminal that is electrically bonded to the secondconductive plate,

wherein the output terminal has a portion that extends to a side awayfrom the first conductive plate in the first direction, and is exposedfrom the sealing resin.

The following will describe semiconductor devices B10 to B30 accordingto a second aspect with reference to FIGS. 33 to 50. Note that, in thefollowing description, the same reference numerals are given to the sameor similar components as those in the above-described semiconductordevices A10 to A50, and descriptions of these components are omitted orsimplified as appropriate.

The semiconductor device B10 according to a first embodiment of thesecond aspect will be described with reference to FIGS. 33 to 42. Thesemiconductor device B10 is provided with the first conductive plate 11,the second conductive plate 12, the plurality of first switchingelements 21, the plurality of second switching elements 22, the firstsupply terminal 31, and the second supply terminal 32. In additionthereto, the semiconductor device B10 is provided with the terminalinsulating member 39, the first conductive wires 411, the secondconductive wires 421, an insulating layer 10′, and the sealing resin 50.In FIG. 34 out of these figures, the sealing resin 50 is transparent,for convenience of understanding. In FIG. 35, for convenience ofunderstanding, the second supply terminal 32 is omitted and the terminalinsulating member 39 is transparent. The sealing resin 50 that istransparent in FIGS. 34 and 35, and the terminal insulating member 39that is transparent in FIG. 35 are indicated by virtual lines(dashed-two dotted lines). Note that the perspective view and the planview of the semiconductor device B10 are identical to FIG. 1 and FIG. 2.

As shown in FIGS. 34 to 38, the first conductive plate 11 is anelectrically conductive member that is made of metal and isplate-shaped, and on which the plurality of first switching elements 21are mounted. The constituent material of the first conductive plate 11is Cu (copper) or a Cu alloy. The first conductive plate 11 has athickness set to 1.5 to 10 mm. The first conductive plate 11 has a firstmain surface 11 a and a first back surface 11 b.

As shown in FIGS. 34 to 38 (excluding FIG. 37), the first substrate 13,which has electrical insulating properties, is bonded to the first mainsurface 11 a of the first conductive plate 11. The first substrate 13 islocated between the plurality of first switching elements 21 and thefirst supply terminal 31 in the first direction x, and extends in thesecond direction y. The first substrate 13 is a ceramic substrate whoseconstituent material is, for example, Al₂O₃ (alumina) or the like, or aprinted-wiring board. The first substrate 13 is bonded to the first mainsurface 11 a with an adhesive (not-shown). The first gate layer 131 andthe first detection layer 132 are arranged on the first substrate 13.The first gate layer 131 and the first detection layer 132 areelectrically conductive, and extend in the second direction y. The firstgate layer 131 and the first detection layer 132 are made of a Cu foil,for example.

As shown in FIGS. 34, 35, 39, and 40, the second conductive plate 12 isan electrically conductive member that is made of metal and isplate-shaped, and on which the plurality of second switching elements 22are mounted. The constituent material and the thickness of the secondconductive plate 12 are the same as the constituent material and thethickness of the first conductive plate 11. The second conductive plate12 has a second main surface 12 a and a second back surface 12 b. Thesecond conductive plate 12 is spaced apart from the first conductiveplate 11 in the first direction x. As shown in, for example, FIG. 37,part of the sealing resin 50 enters a space between the first conductiveplate 11 and the second conductive plate 12 and fills up the space.

As shown in FIGS. 34, 35, and 39, the second substrate 14, which haselectrical insulating properties, is bonded to the second main surface12 a of the second conductive plate 12. The second substrate 14 islocated between the plurality of second switching elements 22 and theoutput terminal 33 in the first direction x, and extends in the seconddirection y. The constituent material of the second substrate 14 is thesame as the constituent material of the first substrate 13. The secondsubstrate 14 is bonded to the second main surface 12 a with an adhesive(not-shown). The second gate layer 141 and the second detection layer142 are arranged on the second substrate 14. The second gate layer 141and the second detection layer 142 are electrically conductive, andextend in the second direction y. The second gate layer 141 and thesecond detection layer 142 are made of a Cu foil, for example.

As shown in FIGS. 34 to 37, the plurality of first switching elements 21are electrically bonded to the first main surface 11 a of the firstconductive plate 11, and are electrically connected to the secondconductive plate 12. Each first switching element 21 is electricallyconnected to the second conductive plate 12 via the first conductivewires 411. Each of the first switching elements 21 has a main surface21A and a back surface 21B.

As shown in FIGS. 34, 35, 39, and 40, the plurality of second switchingelements 22 are semiconductor elements that are electrically bonded to(the second main surface 12 a of) the second conductive plate 12. Eachsecond switching element 22 is electrically connected to the secondsupply terminal 32 via the second conductive wires 421. The secondswitching elements 22 are the same elements as the first switchingelements 21. The plurality of second switching elements 22 are lined upin the second direction y. The second switching elements 22 each havethe main surface 22A and the back surface 22B.

As shown in FIG. 40, the main surface 22A is oriented in the samedirection as that of the second main surface 12 a of the secondconductive plate 12. The main surface 22A is provided with the mainsurface electrode 221 and the gate electrode 223. Furthermore, the backsurface 22B is oriented toward a side opposite to the main surface 22A,and faces the second main surface 12 a. The back surface 22B is providedwith the back surface electrode 222.

A gate voltage for driving the second switching element 22 is applied tothe gate electrode 223. As shown in FIG. 42, the gate electrode 223 islocated between two regions of the main surface electrode 221 that arespaced apart from each other in the first direction x. The gateelectrode 223 has a size smaller than that of any region of the mainsurface electrode 221.

As shown in FIG. 37, the element joining layer 29 is interposed betweenthe back surface 21B of the first switching element 21 and the firstmain surface 11 a of the first conductive plate 11. Furthermore, asshown in FIG. 40, the element joining layer 29 is interposed between theback surface 22B of the second switching element 22 and the second mainsurface 12 a of the second conductive plate 12. The element joininglayers 29 are electrically conductive. The element joining layers 29 arelead-free solders whose main component is Sn (tin), for example. Thefirst switching elements 21 are electrically bonded to the first mainsurface 11 a through die bonding using the element joining layers 29.Similarly, the second switching elements 22 are bonded to the secondmain surface 12 a through die bonding using the element joining layers29.

As shown in FIGS. 33 and 35, the first supply terminal 31 is anelectrically conductive member that is made of metal, is plate-shaped,and is electrically bonded to the first conductive plate 11. The firstsupply terminal 31 serves as a positive electrode (P terminal) of thesemiconductor device B10. The constituent material of the first supplyterminal 31 is, for example, Cu. The surface of the first supplyterminal 31 may also be plated with Ni (nickel). The first supplyterminal 31 has a thickness set to 0.5 to 1.5 mm. The first supplyterminal 31 has the comb tooth-shaped portions 311 and the externalconnection portion 312. The comb tooth-shaped portions 311 are adjacentto the first substrate 13 in the first direction x, and overlap with thefirst conductive plate 11 as viewed in a plan view. The combtooth-shaped portions 311 are electrically bonded to the first mainsurface 11 a of the first conductive plate 11. The method of joining thecomb tooth-shaped portions 311 to the first main surface 11 a may besolder joining or ultrasonic joining. The external connection portion312 is band-shaped and extends, from the comb tooth-shaped portions 311,to a side away from the second conductive plate 12 in the firstdirection x. The external connection portion 312 is partially exposed tothe outside from the semiconductor device B10.

As shown in FIG. 34, the second supply terminal 32 is an electricallyconductive member that is made of metal, is plate-shaped, and has aregion that overlaps with the first supply terminal 31 as viewed in aplan view. The second supply terminal 32 is spaced apart from all of thefirst conductive plate 11, the second conductive plate 12, and the firstsupply terminal 31 in the thickness direction z. Accordingly, the secondsupply terminal 32 is electrically insulated from all of the firstconductive plate 11, the second conductive plate 12, and the firstsupply terminal 31. The second supply terminal 32 is electricallyconnected to the plurality of second switching elements 22. The secondsupply terminal 32 serves as a negative electrode (N terminal) of thesemiconductor device B10. The constituent material and the thickness ofthe second supply terminal 32 are the same as the constituent materialand the thickness of the first supply terminal 31. The surface of thesecond supply terminal 32 may also be plated with Ni. The second supplyterminal 32 has the first band-shaped portion 321, the plurality ofsecond band-shaped portions 322, and the external connection portion323.

As shown in FIGS. 38 to 40, the insulator 324 is interposed between theleading end of the second band-shaped portion 322 (of the second supplyterminal 32), and the first main surface 11 a of the first conductiveplate 11. The insulator 324 is an electrically-insulating adhesive. Theconstituent material of the insulator 324 is, for example, an epoxyresin or polyimide. The second band-shaped portions 322 are bonded tothe first main surface 11 a via the insulators 324. Due to theinsulators 324, the second supply terminal 32 is bonded to the firstconductive plate 11, and electric insulation between the firstconductive plate 11 and the second supply terminal 32 is ensured.

As shown in FIGS. 33, 34, and 38, the terminal insulating member 39 isplate shaped, and is interposed between the first supply terminal 31 andthe second supply terminal 32 in the thickness direction z. The terminalinsulating member 39 has electrical insulating properties. Theconstituent material of the terminal insulating member 39 is a ceramicsuch as Al₂O₃, for example. The terminal insulating member 39 has athickness set to 0.1 to 1.0 mm. In the semiconductor device B10, theterminal insulating member 39 is in contact with both the first supplyterminal 31 and the second supply terminal 32.

As shown in FIG. 34, part of every second band-shaped portion 322 of thesecond supply terminal 32 is located between two adjacent firstswitching elements 21. Accordingly, in the semiconductor device B10, asecond band-shaped portion 322 extends between two adjacent firstswitching elements 21 toward the second conductive plate 12.Furthermore, each of the second switching elements 22 faces thecorresponding single second band-shaped portion 322 in the firstdirection x.

As shown in FIGS. 33 to 35, the output terminal 33 is an electricallyconductive member that is made of metal, is plate-shaped, and iselectrically bonded to the second conductive plate 12. Electric powerinput to the semiconductor device B10 from the first supply terminal 31and the second supply terminal 32 is converted by the plurality of firstswitching elements 21 and the plurality of second switching elements 22,and the converted power is output to the output terminal 33. Theconstituent material and the thickness of the output terminal 33 are thesame as the constituent material and the thickness of the first supplyterminal 31. The surface of the output terminal 33 may also be platedwith Ni. The output terminal 33 has the comb tooth-shaped portions 331and the external connection portion 332. The comb tooth-shaped portions331 are adjacent to the second substrate 14 in the first direction x,and overlap with the second conductive plate 12 as viewed in a planview. The comb tooth-shaped portions 331 are electrically bonded to thesecond main surface 12 a of the second conductive plate 12. The methodof joining the comb tooth-shaped portions 331 to the second main surface12 a may be solder joining or ultrasonic joining. The externalconnection portion 332 is band-shaped and extends, from the combtooth-shaped portions 331, to a side away from the first conductiveplate 11 in the first direction x. Therefore, the external connectionportion 332 extends toward the side opposite to the side to which theexternal connection portion 312 of the first supply terminal 31 and theexternal connection portion 323 of the second supply terminal 32 extend.The external connection portion 332 is partially exposed to the outsidefrom the semiconductor device B10.

As shown in FIG. 35, the semiconductor device B10 is provided with thefirst gate terminal 341. The first gate terminal 341 is electricallyconductive, and is arranged opposing, in the second direction y, thefirst gate layer 131 while extending to a side away from the first gatelayer 131. As shown in FIGS. 2 and 33, the first gate terminal 341 ispartially exposed to the outside of the semiconductor device B10. Theconstituent material of the first gate terminal 341 is, for example, Cu.The surface of the first gate terminal 341 is plated with Sn.

As shown in FIG. 35, the first terminal wire 451 is provided. The firstterminal wire 451 is electrically conductive, and connects the firstgate terminal 341 and the first gate layer 131. The constituent materialof the first terminal wire 451 is, for example, Al (aluminum). The firstgate terminal 341 is electrically connected to the first gate layer 131via the first terminal wire 451.

As shown in FIGS. 35 and 41, the semiconductor device B10 is providedwith the first gate wires 431. The first gate wires 431 are electricallyconductive, and connect the gate electrodes 213 of the first switchingelements 21 and the first gate layer 131. The constituent material ofthe first gate wires 431 is Al, for example. The gate electrode 213 iselectrically connected to the first gate layer 131 via the first gatewire 431. Accordingly, the first gate terminal 341 is electricallyconnected to the gate electrode 213. The semiconductor device B10 has aconfiguration in which the plurality of first switching elements 21 aredriven upon application of a gate voltage to the first gate terminal341.

As shown in FIG. 35, the semiconductor device B10 is provided with thesecond gate terminal 342. The second gate terminal 342 is electricallyconductive, and is arranged opposing, in the second direction y, thesecond gate layer 141 while extending to a side away from the secondgate layer 141. As shown in FIG. 33, the second gate terminal 342 ispartially exposed to the outside of the semiconductor device B10. Theconstituent material of the second gate terminal 342 is the same as theconstituent material of the first gate terminal 341. The surface of thesecond gate terminal 342 is plated with Sn.

As shown in FIG. 35, the semiconductor device B10 is provided with thesecond terminal wire 452. The second terminal wire 452 is electricallyconductive, and connects the second gate terminal 342 and the secondgate layer 141. The constituent material of the second terminal wire 452is the same as the constituent material of the first terminal wire 451.The second gate terminal 342 is electrically connected to the secondgate layer 141 via the second terminal wire 452.

As shown in FIGS. 35 and 42, the semiconductor device B10 is providedwith the second gate wires 432. The second gate wires 432 areelectrically conductive, and connect the gate electrodes 223 of thesecond switching elements 22 and the second gate layer 141. Theconstituent material of the second gate wires 432 is the same as theconstituent material of the first gate wires 431. The gate electrodes223 are electrically connected to the second gate layer 141 via thesecond gate wires 432. Accordingly, the second gate terminal 342 iselectrically connected to the gate electrodes 223. In the semiconductordevice B10, the plurality of second switching elements 22 are drivenupon application of a gate voltage to the second gate terminal 342.

As shown in FIG. 35, the semiconductor device B10 is provided with thefirst detection terminal 351. The first detection terminal 351 iselectrically conductive, and is arranged opposing, in the seconddirection y, the first detection layer 132 while extending to a sideaway from the first detection layer 132. As shown in FIGS. 2 and 33, thefirst detection terminal 351 is partially exposed to the outside of thesemiconductor device B10. The first detection terminal 351 is spacedapart from the first gate terminal 341 in the first direction x. Theconstituent material of the first detection terminal 351 is the same asthe constituent material of the first gate terminal 341. The surface ofthe first detection terminal 351 is plated with Sn.

As shown in FIG. 35, the semiconductor device B10 is provided with thethird terminal wire 453. The third terminal wire 453 is electricallyconductive, and connects the first detection terminal 351 and the firstdetection layer 132. The constituent material of the third terminal wire453 is the same as the constituent material of the first terminal wire451. The first detection terminal 351 is electrically connected to thefirst detection layer 132 via the third terminal wire 453.

As shown in FIGS. 35 and 41, the semiconductor device B10 is providedwith the first detection wires 441. The first detection wires 441 areelectrically conductive, and connect the main surface electrodes 211 ofthe first switching elements 21 and the first detection layer 132. Theconstituent material of the first detection wires 441 is, for example,Al. Each first detection wire 441 is connected to one of the regions ofthe corresponding main surface electrode 211. The main surfaceelectrodes 211 are electrically connected to the first detection layer132 via the first detection wires 441. Accordingly, the first detectionterminal 351 is electrically connected to the main surface electrodes211. In the semiconductor device B10, a source current (or emittercurrent) that is input to the plurality of first switching elements 21is detected by the first detection terminal 351.

As shown in FIG. 35, the semiconductor device B10 is provided with thesecond detection terminal 352. The second detection terminal 352 iselectrically conductive, and is arranged opposing, in the seconddirection y, the second detection layer 142 while extending to a sideaway from the second detection layer 142. As shown in FIGS. 2 and 33,the second detection terminal 352 is partially exposed to the outside ofthe semiconductor device B10. The second detection terminal 352 isspaced apart from the second gate terminal 342 in the first direction x.The constituent material of the second detection terminal 352 is thesame as the constituent material of the first gate terminal 341. Thesurface of the second detection terminal 352 is plated with Sn.

As shown in FIG. 35, the semiconductor device B10 is provided with thefourth terminal wire 454. The fourth terminal wire 454 is electricallyconductive, and connects the second detection terminal 352 and thesecond detection layer 142. The constituent material of the fourthterminal wire 454 is the same as the constituent material of the firstterminal wire 451. The second detection terminal 352 is electricallyconnected to the second detection layer 142 via the fourth terminal wire454.

As shown in FIGS. 35 and 42, the semiconductor device B10 is providedwith the second detection wires 442. The second detection wires 442 areelectrically conductive, and connect the main surface electrodes 221 ofthe second switching elements 22 and the second detection layer 142. Theconstituent material of the second detection wires 442 is the same asthe constituent material of the first detection wires 441. Each seconddetection wire 442 is connected to one of the regions of thecorresponding main surface electrode 221. The main surface electrodes221 are electrically connected to the second detection layer 142 via thesecond detection wires 442. Accordingly, the second detection terminal352 is electrically connected to the main surface electrodes 221. In thesemiconductor device B10, a source current (or a drain current) that isinput to the plurality of second switching elements 22 is detected bythe second detection terminal 352.

As shown in FIG. 35, the semiconductor device B10 is provided with thedevice current detection terminal 36. The device current detectionterminal 36 is electrically conductive, and is arranged between thefirst detection terminal 351 and the second detection terminal 352 inthe first direction x, and is arranged opposing the first conductiveplate 11 in the second direction y. The device current detectionterminal 36 extends to a side away from the first conductive plate 11 inthe second direction y. As shown in FIG. 33, the device currentdetection terminal 36 is partially exposed to the outside of thesemiconductor device B10. The constituent material of the device currentdetection terminal 36 is the same as the constituent material of thefirst gate terminal 341. The surface of the device current detectionterminal 36 is plated with Sn.

As shown in FIG. 35, the semiconductor device B10 is provided with thefifth terminal wire 455. The fifth terminal wire 455 is electricallyconductive, and connects the device current detection terminal 36 andthe first main surface 11 a of the first conductive plate 11. Theconstituent material of the fifth terminal wire 455 is the same as theconstituent material of the first terminal wire 451. The device currentdetection terminal 36 is electrically connected to the first conductiveplate 11 via the fifth terminal wire 455. In the semiconductor deviceB10, a current that flows through the first conductive plate 11 isdetected by the device current detection terminal 36.

As shown in FIGS. 34 to 37, the first conductive wires 411 areelectrically conductive members that connect the main surface electrodes211 of the first switching elements 21 and the second main surface 12 aof the second conductive plate 12. The first conductive wires 411 arethin metal wires that extend in the first direction x. The firstconductive wires 411 are connected to the respective regions of the mainsurface electrodes 211. In the semiconductor device B10, the pluralityof first switching elements 21 are electrically connected to the secondconductive plate 12 via the first conductive wires 411. The constituentmaterial of the first conductive wires 411 is, for example, Al.

As shown in FIG. 34, the second conductive wires 421 are electricallyconductive members that connect the second band-shaped portions 322 ofthe second supply terminal 32 and the main surface electrodes 221 of thesecond switching elements 22. The second conductive wires 421 are thinmetal wires that extend in the first direction x. The second conductivewires 421 are connected to the respective regions of the main surfaceelectrodes 221. In the semiconductor device B10, the second band-shapedportions 322 are electrically connected to the main surface electrodes221 via the second conductive wires 421. The constituent material of thesecond conductive wires 421 is the same as the constituent material ofthe first conductive wires 411.

As shown in FIGS. 38 and 39, the insulating layer 10′ includes twoseparate regions (a first region 103 and a second region 104), which arerespectively bonded to the first back surface 11 b of the firstconductive plate 11 and the second back surface 12 b of the secondconductive plate 12. The first region 103 and the second region 104 arespaced apart from each other in the first direction x. The insulatinglayer 10′ (that is, the first region 103 and the second region 104) haselectrical insulating properties and relatively high heat conductivity.The constituent material of the insulating layer 10′ is, for example, aceramic such as Al₂O₃ or AlN (aluminum nitride), or a heat dissipationsheet whose main component is a synthetic resin. The thickness of theinsulating layer 10′ is smaller than the thicknesses of the firstconductive plate 11 and the second conductive plate 12, and is set to0.1 to 1.0 mm. Due to the insulating layer 10′, the first conductiveplate 11 and the second conductive plate 12 are electrically insulatedfrom the outside of the semiconductor device B10. The insulating layer10′ may be omitted. In this case, a configuration is such that both thefirst back surface 11 b and the second back surface 12 b are coveredwith the sealing resin 50.

As shown in FIGS. 33 to 40, the sealing resin 50 covers the firstconductive plate 11, the second conductive plate 12, the plurality offirst switching elements 21, and the plurality of second switchingelements 22. The sealing resin 50 has electrical insulating properties.The constituent material of the sealing resin 50 is, for example, ablack epoxy resin. The sealing resin 50 has the front surface 51, theback surface 52, the pair of first side surfaces 531, and the pair ofsecond side surfaces 532.

As shown in FIGS. 36 to 40, the front surface 51 is oriented in the samedirection as that of the first main surface 11 a of the first conductiveplate 11 and the second main surface 12 a of the second conductive plate12. The back surface 52 is oriented in the same direction as that of thefirst back surface 11 b of the first conductive plate 11 and the secondback surface 12 b of the second conductive plate 12. The insulatinglayer 10′ (the first region 103 and the second region 104) is exposedfrom the back surface 52. A heat dissipation member may also be bondedto the exposed surface of the insulating layer 10′.

Each of the pair of first side surfaces 531 is connected to both thefront surface 51 and the back surface 52, and are spaced apart from eachother in the first direction x (see FIG. 4). The external connectionportion 312 of the first supply terminal 31, the external connectionportion 323 of the second supply terminal 32, and the terminalinsulating member 39 are partially exposed from one of the first sidesurfaces 531. The external connection portion 332 of the output terminal33 is partially exposed from the other one of the first side surfaces531. Each of the pair of second side surfaces 532 is connected to boththe front surface 51 and the back surface 52, and are spaced apart fromeach other in the second direction y (see FIG. 5). Both ends, in thefirst direction x, of each second side surface 532 are connected to thepair of first side surfaces 531. The first gate terminal 341, the secondgate terminal 342, the first detection terminal 351, the seconddetection terminal 352, and the device current detection terminal 36 arepartially exposed from one of the second side surfaces 532 (see FIG.33).

As shown in e.g. FIG. 33, the sealing resin 50 is provided with, on itsback surface 52, a plurality of grooves 54 that extend in the seconddirection y. The plurality of grooves 54 are located at both ends, inthe first direction x, of the back surface 52. The plurality of grooves54 each extend from one of the second side surfaces 532 to the other oneof the second side surfaces 532.

The circuit configuration of the semiconductor device B10 is identicalto that shown in FIG. 14, and the way in which operation of theswitching elements and the like that constitute this circuit operate isalso the same as the content described with reference to FIG. 14.Furthermore, an example of usage of the semiconductor device B10 is thesame as that described with reference to FIG. 15.

The following will describe the functions and effects of thesemiconductor device B10. According to the configuration of thesemiconductor device B10, the first conductive plate 11 and the secondconductive plate 12 function as heat dissipation members andelectrically conductive members in the semiconductor device B10. Thethicknesses of the first conductive plate 11 and the second conductiveplate 12 are larger than the thickness of a conductive layer made of,for example, a metal foil. Accordingly, in the first direction x and thesecond direction y, which are perpendicular to the thickness directionz, the cross-sectional areas of the first conductive plate 11 and thesecond conductive plate 12 are larger than the cross-sectional area of aconductive layer made of a metal foil. Accordingly, in the firstdirection x and the second direction y, the thermal resistances per unitlength of the first conductive plate 11 and the second conductive plate12 are lower than the thermal resistance per unit length of a conductivelayer made of a metal foil. In other words, in the first direction x andthe second direction y, heat is more likely to be transferred over awide range through the first conductive plate 11 and the secondconductive plate 12 than a conductive layer made of a metal foil.Therefore, with the semiconductor device B10, it is possible to improvethe heat dissipation.

With the improvement in the heat dissipation of the semiconductor deviceB10, it is possible to reduce the electric resistance of the firstconductive plate 11 and the second conductive plate 12. Therefore, withthe semiconductor device B10, it is possible to suppress power loss.

Furthermore, the second supply terminal 32 has a region that overlapswith the first supply terminal 31 as viewed in a plan view. According tothis configuration, noise generated from the second supply terminal 32interferes with noise generated from the first supply terminal 31, andthus the self-inductance of the first supply terminal 31 is reduced.Similarly, noise generated from the first supply terminal 31 interfereswith noise generated from the second supply terminal 32, and thus theself-inductance of the second supply terminal 32 is reduced. In thisway, with the reduction in the self-inductance of the first supplyterminal 31 and the second supply terminal 32, it is possible to furtherreduce power loss of the semiconductor device B10. Furthermore, it isalso possible to reduce a surge voltage that is applied to the pluralityof first switching elements 21 and the plurality of second switchingelements 22. Note that similar technical effects can also be achieved bythe semiconductor devices according to the first aspect.

The semiconductor device B10 is provided with the terminal insulatingmember 39, which has electrical insulating properties and is interposedbetween the first supply terminal 31 and the second supply terminal 32.With this, it is possible to further reduce the distance, in thethickness direction z, between the first supply terminal 31 and thesecond supply terminal 32, while ensuring electric insulation betweenthe first supply terminal 31 and the second supply terminal 32.Accordingly, it is possible to further reduce the self-inductance of thefirst supply terminal 31 and the second supply terminal 32.

The first band-shaped portion 321 and the plurality of secondband-shaped portions 322 of the second supply terminal 32 overlap withthe first conductive plate 11 as viewed in a plan view. Also, the secondband-shaped portions 322 are electrically connected to the main surfaceelectrodes 221 of the second switching elements 22 via the secondconductive wires 421, which extend in the first direction x.Accordingly, it is possible to suppress an increase in size of thesemiconductor device B10 as viewed in a plan view.

The plurality of first switching elements 21 are lined up in the seconddirection y, and part of every second band-shaped portion 322 is locatedbetween two adjacent first switching elements 21. Accordingly, it ispossible to suppress an increase in size, in the second direction y, ofthe semiconductor device B10. In this case, the plurality of secondswitching elements 22 are lined up in the second direction y, and eachof the second switching elements 22 faces the corresponding singlesecond band-shaped portion 322 in the first direction x. Accordingly, itis possible to shorten the electrical connection paths from theplurality of second switching elements 22 to the second supply terminal32, while further suppressing an increase in size, in the seconddirection y, of the semiconductor device B10.

The semiconductor device B10 is provided with the second conductivewires 421, which are connected to the second band-shaped portions 322 ofthe second supply terminal 32 and the main surface electrodes 221 of thesecond switching elements 22, and extend in the first direction x.Accordingly, the conductive paths between the plurality of secondswitching elements 22 and the second supply terminal 32 extend in thefirst direction x. The semiconductor device B10 is also provided withthe first conductive wires 411, which are connected to the firstswitching elements 21 and the second main surface 12 a of the secondconductive plate 12, and extend in the first direction x. Accordingly,the conductive paths between the plurality of first switching elements21 and the second conductive plate 12 extend in the first direction x.Therefore, since the conductive paths extending in the first direction xare formed in the semiconductor device B10, it is possible to improvethe dielectric strength voltage of the semiconductor device B10.

The second band-shaped portions 322 of the second supply terminal 32 arebonded to the first main surface 11 a of the first conductive plate 11via the insulators 324, which have electrical insulating properties.Accordingly, the second supply terminal 32 can be supported on the firstconductive plate 11. Furthermore, when the second conductive wires 421are bonded to the second band-shaped portions 322 using wire bonding,the second band-shaped portions 322 are subjected to a reactive forceexerted from the first conductive plate 11, thus making it possible tosufficiently ensure the joining strength between the second conductivewires 421 and the second band-shaped portions 322.

The first substrate 13, which has electrical insulating properties, isbonded to the first main surface 11 a of the first conductive plate 11.The first substrate 13 is provided with the first gate layer 131, whichis electrically connected to both the gate electrodes 213 of the firstswitching elements 21 and the first gate terminal 341. Furthermore, thefirst gate terminal 341, which is electrically connected to the firstgate layer 131, is spaced apart from the first conductive plate 11 (seee.g. FIG. 34). Accordingly, in the semiconductor device B10, aconductive path for driving the plurality of first switching elements 21can be configured with the first gate layer 131 electrically insulatedfrom the first conductive plate 11.

The second substrate 14, which has electrical insulating properties, isbonded to the second main surface 12 a of the second conductive plate12. The second substrate 14 is provided with the second gate layer 141,which is electrically connected to both the gate electrodes 223 of thesecond switching elements 22 and the second gate terminal 342.Furthermore, the second gate terminal 342, which is electricallyconnected to the second gate layer 141, is spaced apart from the secondconductive plate 12. Accordingly, in the semiconductor device B10, aconductive path for driving the plurality of second switching elements22 can be configured with the second gate layer 141 electricallyinsulated from the second conductive plate 12.

The semiconductor device B10 is provided with the sealing resin 50,which covers the first conductive plate 11, the second conductive plate12, and the like. The first supply terminal 31 and the second supplyterminal 32 have portions that extend to a side away from the secondconductive plate 12 in the first direction x, and are exposed from thesealing resin 50. Furthermore, the semiconductor device B10 is providedwith the output terminal 33, which is electrically bonded to the secondconductive plate 12. The output terminal 33 has a portion that extendsto a side away from the first conductive plate 11 in the first directionx, and is exposed from the sealing resin 50. Accordingly, the firstsupply terminal 31 and the second supply terminal 32 are spaced apartfrom the output terminal 33 in the first direction x, which is the samedirection as that of the conductive path of the semiconductor deviceB10. This can further improve the dielectric strength voltage of thesemiconductor device B10.

The semiconductor device B10 is provided with the insulating layer 10′,which is bonded to the first back surface 11 b of the first conductiveplate 11 and the second back surface 12 b of the second conductive plate12. The insulating layer 10′ is exposed from the back surface 52 of thesealing resin 50. Accordingly, the first conductive plate 11 and thesecond conductive plate 12 are electrically insulated from the outsideof the semiconductor device B10. By making the thickness of theinsulating layer 10′ as small as possible, it is possible to reduce thethickness of the semiconductor device B10.

The insulating layer 10′ includes the first region 103 bonded to thefirst conductive plate 11, and the second region 104 bonded to thesecond conductive plate 12, and the first region 103 and the secondregion 104 are spaced apart from each other in the first direction x.Accordingly, when manufacturing the semiconductor device B10, it ispossible to suppress warpage that may occur in the insulating layer 10′,and avoid excessive bending distortion of the first conductive plate 11and the second conductive plate 12.

The sealing resin 50 is provided with the plurality of grooves 54, whichare recessed from the back surface 52 in the thickness direction z andextend in the second direction y. The plurality of grooves 54 arelocated at both ends, in the first direction x, of the back surface 52.With this, the surface, in the first direction x, of the back surface 52including the plurality of grooves 54 is further extended, and thus itis possible to further improve the dielectric strength voltage of thesemiconductor device B10.

A semiconductor device B20 according to a second embodiment of thesecond aspect will be described with reference to FIGS. 43 to 47. InFIG. 43 out of these figures, the sealing resin 50 is indicated by avirtual line.

In the semiconductor device B20, the first electrical connection leads412 are used in place of the first conductive wires 411, and the secondelectrical connection leads 422 are used in place of the secondconductive wires 421.

As shown in FIGS. 43 to 45, the first electrical connection leads 412are electrically conductive members that connect the main surfaceelectrodes 211 of the first switching elements 21 and the second mainsurface 12 a of the second conductive plate 12. The first electricalconnection leads 412 are metal plates that are band-shaped and extend inthe first direction x, and are bent into a hook shape in the thicknessdirection z. The constituent material of the first electrical connectionleads 412 is Cu or a Cu alloy. One end of each first electricalconnection lead 412 is electrically bonded to a main surface electrode211 via a conductive joint layer 49. The other end of the firstelectrical connection lead 412 is electrically bonded to the second mainsurface 12 a via a conductive joint layer 49. The conductive jointlayers 49 are electrically conductive, and are lead-free solder whosemain component is Sn (tin), for example.

As shown in FIGS. 43, 46, and 47, the second electrical connection leads422 are electrically conductive members that connect the secondband-shaped portions 322 of the second supply terminal 32 and the mainsurface electrodes 221 of the second switching elements 22. The secondelectrical connection leads 422 are metal plates that are band-shapedand extend in the first direction x, and are bent into a hook shape inthe thickness direction z. The constituent material of the secondelectrical connection leads 422 is the same as the constituent materialof the first electrical connection leads 412. One end of each secondelectrical connection lead 422 is electrically bonded to a secondband-shaped portion 322 via a conductive joint layer 49. The other endof the second electrical connection lead 422 is electrically bonded to amain surface electrode 221 via a conductive joint layer 49.

The following will describe the functions and effects of thesemiconductor device B20. According to the configuration of thesemiconductor device B20, the same first conductive plate 11 and secondconductive plate 12 as those of the above-described semiconductor deviceB10 are provided. Since the first conductive plate 11 and the secondconductive plate 12 function as heat dissipation members (andelectrically conductive members) in the semiconductor device B20, it ispossible to improve the heat dissipation, also with the semiconductordevice B20.

The semiconductor device B20 is provided with the first electricalconnection leads 412 and the second electrical connection leads 422. Thecross-sectional areas of the first electrical connection leads 412 andthe second electrical connection leads 422 are larger than thecross-sectional areas of the first conductive wires 411 and the secondconductive wires 421. Accordingly, the electric resistance of the firstelectrical connection leads 412 and the second electrical connectionleads 422 is lower than the electric resistance of the first conductivewires 411 and the second conductive wires 421. Accordingly, it ispossible to suppress power loss of the semiconductor device B20,compared to that of the semiconductor device B10.

A semiconductor device B30 according to a third embodiment of the secondaspect will be described with reference to FIGS. 48 to 50. In FIG. 48out of these figures, the sealing resin 50 is indicated by a virtualline.

The semiconductor device B30 differs from the semiconductor device B10in that the first electrical connection leads 412 are used in place ofthe first conductive wires 411, and differs in a configuration of thesecond band-shaped portions 322 of the second supply terminal 32. Thefirst electrical connection leads 412 have the same configuration as theconfiguration of the first electrical connection leads 412 of theabove-described semiconductor device B20.

As shown in FIG. 48, the leading ends of the second band-shaped portions322 of the second supply terminal 32 extend to positions at which theyoverlap with the main surface electrodes 221 of the second switchingelements 22, as viewed in a plan view. As shown in FIGS. 49 and 50, theleading ends of the second band-shaped portions 322 are bent into a hookshape in the thickness direction z. The leading ends of the secondband-shaped portions 322 are electrically bonded to the main surfaceelectrodes 211 via conductive joint layers 49. Accordingly, the mainsurface electrodes 221 are electrically connected to the second supplyterminal 32 without any of the second conductive wires 421 and thesecond electrical connection leads 422. In the semiconductor device B30,since the second band-shaped portions 322 are not bonded to the firstmain surface 11 a of the first conductive plate 11, there is no need toprovide the insulators 324.

The following will describe the functions and effects of thesemiconductor device B30. Also in the semiconductor device B30, thefirst conductive plate 11 and the second conductive plate 12 function asheat dissipation members (and electrically conductive members), andthus, it is possible to improve the heat dissipation.

The second band-shaped portions 322 of the second supply terminal 32 areconnected to the main surface electrodes 221 of the second switchingelements 22. Accordingly, in the semiconductor device B30, there is noneed to provide any of the second conductive wires 421, the secondelectrical connection leads 422, and the insulators 324. It is thuspossible to reduce the number of components needed to manufacture thesemiconductor device B30.

In the embodiments of the second aspect, a plurality of diodes (such asschottky barrier diodes) constituting parallel circuits that correspondto the first switching elements 21 may also be electrically bonded tothe first main surface 11 a of the first conductive plate 11.Furthermore, a plurality of diodes constituting parallel circuits thatcorrespond to the second switching elements 22 may also be electricallybonded to the second main surface 12 a of the second conductive plate12. By providing the plurality of diodes, it is possible to avoid, whenthe plurality of first switching elements 21 are driven, the generationof a reverse current from flowing through the first switching elements21 even if a back electromotive force is generated by the switching.Similarly, it is also possible to avoid, when the plurality of secondswitching elements 22 are driven, the generation of a reverse currentfrom flowing through the second switching elements 22.

The present invention is not limited to the foregoing embodiments. Thespecific configurations of the components of the present invention canbe designed and modified in various ways.

The invention claimed is:
 1. A semiconductor device comprising: a first conductive plate including a first main surface perpendicular to a thickness direction of the first conductive plate; a single second conductive plate including a second main surface perpendicular to the thickness direction, the single second conductive plate being spaced apart from the first conductive plate in a first direction perpendicular to the thickness direction; a plurality of first switching elements, each electrically bonded to the first conductive plate and electrically connected to the single second conductive plate; a plurality of second switching elements, each electrically bonded to the single second conductive plate; a first supply terminal electrically bonded to the first conductive plate, the first supply terminal being flat as a whole and comprising a single flat lower surface held in direct contact with the first conductive plate; and a second supply terminal having a region that overlaps with the first supply terminal as viewed in the thickness direction, the second supply terminal being spaced apart from the first conductive plate and the first supply terminal in the thickness direction, wherein the second supply terminal is electrically connected to the plurality of second switching elements.
 2. The semiconductor device according to claim 1, further comprising: an insulating member interposed between the first supply terminal and the second supply terminal in the thickness direction; and a sealing resin that covers the first conductive plate, the second conductive plate, the plurality of first switching elements, and the plurality of second switching elements, wherein the insulating member comprises a portion protruding to an outside of the sealing resin.
 3. The semiconductor device according to claim 2, wherein the first supply terminal and the second supply terminal each have an exposed portion that is exposed from the sealing resin, and the exposed portion extends to a side away from the second conductive plate in the first direction.
 4. The semiconductor device according to claim 3, further comprising an output terminal electrically bonded to the second conductive plate, wherein the output terminal has an exposed portion that is exposed from the sealing resin, and the exposed portion of the output terminal extends to a side away from the first conductive plate in the first direction.
 5. The semiconductor device according to claim 3, further comprising an insulating layer, wherein the first conductive plate has a first back surface on a side opposite to the first main surface, the second conductive plate has a second back surface on a side opposite to the second main surface, and the sealing resin has a back surface that is oriented toward the same side, in the thickness direction, as the side toward which the first back surface and the second back surface are oriented, and the insulating layer is bonded to the first back surface and the second back surface, and is exposed from the back surface of the sealing resin.
 6. The semiconductor device according to claim 5, wherein the insulating layer includes a first region bonded to the first back surface, and a second region bonded to the second back surface, and the first region and the second region are spaced apart from each other in the first direction.
 7. The semiconductor device according to claim 2, wherein the sealing resin is provided with, on the back surface thereof, a plurality of grooves that extend in the second direction, and the plurality of grooves include a first group of grooves and a second group of grooves, and the first group and the second group are spaced apart from each other in the first direction.
 8. The semiconductor device according to claim 2, wherein said portion of the insulating member protruding to the outside of the sealing resin is greater in area than respective portions of the first supply terminal and the second supply terminal that overlap with said portion of the insulating member.
 9. The semiconductor device according to claim 1, wherein the first conductive plate and the second conductive plate are made of a material that contains Cu.
 10. The semiconductor device according to claim 1, wherein each of the plurality of second switching elements is provided with a main surface electrode, the second supply terminal includes a first band-shaped portion and a plurality of second band-shaped portions, the first band-shaped portion extending in a second direction perpendicular to the thickness direction and the first direction, and the plurality of second band-shaped portions extending from the first band-shaped portion toward the second conductive plate and being spaced apart from each other in the second direction, and the plurality of second band-shaped portions are respectively electrically connected to the main surface electrodes of the plurality of second switching elements.
 11. The semiconductor device according to claim 10, further comprising a plurality of electrical connection leads that connect the plurality of second band-shaped portions and the plurality of second switching elements to each other, wherein each of the plurality of electrical connection leads extends in the first direction.
 12. The semiconductor device according to claim 10, wherein each of the plurality of second band-shaped portions is bonded to the first main surface of the first conductive plate via insulators.
 13. The semiconductor device according to claim 10, wherein each of the plurality of second band-shaped portions is bonded to the main surface electrode of a corresponding one of the plurality of second switching elements.
 14. The semiconductor device according to claim 10, wherein the plurality of first switching elements are spaced apart from each other in the second direction, and one of the plurality of second band-shaped portions is located between two adjacent first switching elements of the plurality of first switching elements.
 15. The semiconductor device according to claim 10, wherein the plurality of second switching elements are spaced apart from each other in the second direction, and the plurality of second switching elements respectively face the plurality of second band-shaped portions in the first direction.
 16. The semiconductor device according to claim 1, further comprising: a first substrate; a first gate layer; and a first gate terminal, wherein the first substrate extends in the second direction, has an electrical insulating property, and is bonded to the first main surface of the first conductive plate, the first gate layer extends in the second direction, is electrically conductive, and is bonded to the first substrate, the first gate terminal is spaced apart from the first conductive plate, and is electrically connected to the first gate layer, and the plurality of first switching elements are electrically connected to the first gate layer.
 17. The semiconductor device according to claim 16, further comprising: a second substrate; a second gate layer; and a second gate terminal, wherein the second substrate extends in the second direction, has an electrical insulating property, and is bonded to the second main surface of the second conductive plate, the second gate layer extends in the second direction, is electrically conductive, and is bonded to the second substrate, the second gate terminal is spaced apart from the second conductive plate, and is electrically connected to the second gate layer, and the plurality of second switching elements are electrically connected to the second gate layer.
 18. The semiconductor device according to claim 1, further comprising an insulating layer including a main surface perpendicular to the thickness direction, wherein the first conductive plate and the second conductive plate are bonded to the main surface of the insulating layer, and the first conductive plate and the second conductive plate have a thickness that is larger than a thickness of the insulating layer.
 19. The semiconductor device according to claim 18, wherein the thickness of the first conductive plate and the second conductive plate is 1.5 to 10 mm.
 20. The semiconductor device according to claim 18, wherein the thickness of the first conductive plate and the second conductive plate is three to one hundred times as large as the thickness of the insulating layer.
 21. The semiconductor device according to claim 18, further comprising a metal layer, wherein the insulating layer has a back surface on a side opposite to the main surface, and the metal layer is bonded to the back surface of the insulating layer, and the metal layer has a thickness that is smaller than the thickness of the first conductive plate and the second conductive plate.
 22. The semiconductor device according to claim 21, further comprising a heat radiator bonded to the metal layer.
 23. The semiconductor device according to claim 18, wherein the first conductive plate and the second conductive plate each have a first layer and a second layer, the first layer being bonded to the main surface of the insulating layer, and the second layer being located on a side of the first layer opposite to the insulating layer in the thickness direction, and the second layer has a thickness that is larger than a thickness of the first layer.
 24. A semiconductor device, comprising: a first conductive plate including a first main surface perpendicular to a thickness direction of the first conductive plate; a second conductive plate including a second main surface perpendicular to the thickness direction, the second conductive plate being spaced apart from the first conductive plate in a first direction perpendicular to the thickness direction; a plurality of first switching elements electrically bonded to the first conductive plate and electrically connected to the second conductive plate; a plurality of second switching elements electrically bonded to the second conductive plate; a first supply terminal electrically bonded to the first conductive plate; a second supply terminal having a region that overlaps with the first supply terminal as viewed in the thickness direction, the second supply terminal being spaced apart from the first conductive plate and the first supply terminal in the thickness direction, wherein the second supply terminal is electrically connected to the plurality of second switching elements, each of the second switching elements is provided with a main surface electrode, the second supply terminal includes a first band-shaped portion and a plurality of second band-shaped portions, the first band-shaped portion extending in a second direction perpendicular to the thickness direction and the first direction, and the plurality of second band-shaped portions extending from the first band-shaped portion toward the second conductive plate and being spaced apart from each other in the second direction, and the plurality of second band-shaped portions are respectively electrically connected to the main surface electrodes of the plurality of second switching elements; and a plurality of conductive wires that connect the plurality of second band-shaped portions and the plurality of second switching elements to each other, wherein each of the plurality of conductive wires extends in the first direction. 